Blog Archives

‘Dynanet’ Telecoms – ‘Rampdown’ notice

Phased Discontinuation of Production – 31st May 2019 – 31st January 2020

The production of the ‘Dynanet’ family of PDH Transmission telecoms products, first introduced by Nokia over 20 years ago, and continued in recent years by DNWP, is finally being ended.

This product range has well served Public Operator and Private Network Customers across the Telecoms, Utilities, Transport and Public Safety markets with high availability mission critical infrastructure, and indeed some networks are continuing to provide good operational service. 

Essentially almost all the old equipment items, with a very few exceptions such as the TPS64, are being completely discontinued in a phased way according to these milestones, which have already commended:

31st May 2019 – DM8 Multiplexers, DF2-8 Optical Terminals, RPSA

31st October 2019 – DM2 Multiplexers, Subs/Exch & VF Cards, DN2 IU2, Service Terminals, V.28/V.11 DIU

31st January 2020 – DB2, DN2 CU & BPU, G.703 & V.110, DIU, Ethernet I/F, Ring Gen, NDM 19” Subrack, NDA

Should you wish to read the full ‘ramp-down’ notice and know more about obtaining equipment before it is no longer available, then please get in touch.

Continued Supply of Spare Parts – Surplus and Refurbished Items

@YellowsBestLtd satisfies customer product sourcing requirements for current and ‘legacy’ equipment technologies.

For the ‘Dynanet’ range, we should be able to continue to supply refurbished and surplus equipment for as long as required, but the likely effect this discontinuation of production will be to squeeze the availability of remaining stocks, with a consequential impact on pricing.

Hence, it is recommended that if there is anything that might be needed, it would be best to consider purchasing it in good time to ensure availability of items and best prices.  

Here is a list of the main items immediately available from current stocks, though there may be a few additional parts that can be supplied. Hence, please check and if you do have any requirements, please let us know. We look forward to hearing from you.

Part NumberDescription
24204TPSO H/W Module
CC 24002DB2 Branching Unit, B2 2×2 Mb/s 75 ohm
CC 24011DB2 2 Mb/s Switching Unit, X2 75 ohm
CC 24101DN2 Interface Unit (IU2) 2×2 Mb/s 75 ohm
CC 24111DN2 Control Unit (CU) 75 ohm
CF 24186DN2 19″ Subrack
CF 24186.09DN2 Subrack 19″, grey-L91 EMC
CG 24170DN2 Bus Power Unit (BPU)
CG 24171Extended DN2 Bus Power Unit (EBPU)
CU 24013Data Interface Unit (DIU) 2M, nx64k: G.703/704, 75 ohm
T30506.0917-slot DYNANET Subrack
T30851.02Subrack Power Adapter (SPA)
T37870.01NDM ACM2 19in 17-slot subrack
T37871.01NDM DN2 19″ 17-Slot Subrack
T37882.01NDM DC Unit (NDUe)
T37882.02NDM DC Unit (NDUe)
T37885.01NDM Ring Generator
Ring Generator – T37885.01
Part NumberDescription
T37889.01NDM Backup Unit (NBU)
NDM Backup Unit – T37889.01
Part NumberDescription
T65520.01ACL2 RM DC Power Gen
T65580.01ACL2i PF GEN Line Terminal Card
ACL2i PF GEN – T65580
Part NumberDescription
TA 21513Optical Line Terminal Repeater 2-8 M, 1300 nm LED MM/SM
TA 21516Optical Line Terminal Repeater 2-8 M, 1300 nm LASER SM
TC 21101DM34 Mux Card
TC 21301DM8 Multiplex Equipment, 75 ohm
TC 21705Supervisory Substation
TC 21710.01TMS Adapter
TG 21261Ring Generator 25HZ 15W
TU 21122.5Data Interface Unit (DIU) 48..64k V.11 10ch
TU 21124Data Interface Unit (DIU) NX64k V.11/V.35/X.21 2CH
TU 21124.05Data Interface Unit (DIU)
TU 21125Data Interface Unit (DIU) 48..64k with sync, X.21
DIU X.21 – TU 21125
Part NumberDescription
TU 21205Channel Unit SUB/SUB
TU 21206Channel Unit SUB/SUB
Channel Unit Subscriber / Subscriber – TU 21206
Part NumberDescription
TU 21215Channel Unit SUB/EXCH
TU 21216Channel Unit SUB/EXCH
Channel Unit Subscriber / Exchange – TU 21216
Part NumberDescription
TU 21234.20Channel Unit E&M/VF-P, 10 CH, 20 E&M CH
TU 21236.10Channel Unit (CU) 8ch E&M/uP: 2xe&m/vf
TU 21255.01Channel Switch, 4 PORT
TV 21640.08Power Interface Adapter DC
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Mobile Communications for Professional Users

Mission Critical Technologies

For many years, pioneering mobile communications technologies have been developed and implemented to serve the operational needs of professional users, such as public safety, utilities and transport organisations.

Initially based on radio technologies predating the public cellular networks and offering bespoke functionality, these were implemented as individual regional networks. Technology evolved from Analogue to Digital and deployments increased from regional to national rollouts.

We are now on the verge of next generation of mission critical communications with the arrival in the UK of the Emergency Services Network (ESN)

A brief history of PMR

When mobile communications were in their infancy, major organisations with mission critical requirements chose to build their own ‘dedicated’ networks to ensure availability of service. The users of such systems had operational requirements that shaped the technology developments, and gave rise to features such as Press-to-Talk (PTT), instant call set-up, encryption, user priority, 1-to-many and group calling. 

Initially such networks were analogue-based and collectively known as ‘Private Mobile Radio’ (PMR). Inter-operation between systems was rarely possible, though one standard that did evolve was MPT1327 ‘Trunking Radio’, implemented by a range of vendors such as NOKIA and TAIT. Individual organisations built, operated and maintained their own infrastructure.

The next generation of technologies were digitally-based; one of the most widely adopted standards was TETRA. A break-though was the standardisation of the ‘air-interface’ permitting the inter-operability of user mobile terminals with infrastructure from a range of manufacturers, such as NOKIA and Motorola.

In the UK, two nationwide networks were rolled out, AIRWAVE for public safety users and DOLPHIN for professional users. The latter of these hit financial difficulties and was closed. Other regional networks were deployed, such as that on the London Underground, whilst other organisations continued to maintain their analogue-PMR systems.  

ESN is coming

As on show at this year’s @TechXLR8 expo, the Emergency Services Network (ESN) is set to revolutionise professional mobile communications in the UK again, ultimately replacing the existing Airwave TETRA network and offering existing and updated services.  

Essentially, acting as an overlay onto EE’s 4G network, the software from Motorola solutions will deliver an advanced mobile communications experience, including the PTT, group-call, priority and security features demanded by professional users. 

The new service will bring PMR into the modern era with ruggedised mobile-phone-like user terminals providing advanced data capabilities, offering high quality colour-displays, GPS-mapping and location-based services. 

A huge investment in development and rollout is taking place, which will result in additional network capabilities and coverage provided by 500 new base-station sites. The new network will serve the needs of the Police, Fire, Ambulance services as well as other professional users such as local authorities and utility services.

Supporting existing and future requirements

@YellowsBestLtd satisfies new and ‘legacy’ requirements for the operations and maintenance of systems and networks by providing services including consultancy, technical support and hardware repairs, and solutions, with the supply of functional replacements, spare part items and software support.

We would be keen to hear from you regarding your existing or future operational needs; please get in touch.

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Apple macOS 64-bit transition – Software ‘Legacy’ issues

32-bit Application compatibility Issues resulting from macOS updates

Issues have started to appear using existing and older software applications on Apple Macintosh computers with the transition from 32-bit to 64-bit operating systems, commencing with macOS High Sierra 10.13.4, and it’s set to get a whole lot worse!

Current Difficulties

Noticeable problems with applications have surfaced with the update to macOS Mojave.

Strange and unwanted things have crept in. For example:

  • opening a new Finder window causes a new tab to open instead. It’s like the wrong option has been selected – now opening a tab or a window are incorrectly identical. If you want a new Finder window, you need to then select ‘move this tab to a new window’. So suddenly this is a two-stage process 
New Finder window opens a New Tab instead
  • Trying to print from Microsoft Word causes the application to ‘crash’. The work-around for this is its still possible to print by using the toolbar button, instead of selecting ‘print’ from the drop-down menu. But then this doesn’t allow for changing print settings etc.
Microsoft Word quits when trying to print

Promise of worse compatibility problems

This is just the ‘tip of the iceberg’. A whole range of software applications which currently run happily on the Apple Mac are set to become unusable in the next update to macOS. We’re talking about mainstream applications such as Microsoft Office as well as ‘niche’ applications that you may utilise. This appears to represent the biggest shift in software compatibility since the change from Mac ‘Classic’ (OS 9 and before) to Mac OSX, more than 10 years ago.

A warning is displayed when a 32-bit application is launched in macOS High Sierra, and in macOS Mojave the alert appears every 30 days.

The official Apple advice is to ‘contact the application developer’. For the average user, that’s unlikely to achieve anything, particularly for mature applications that perhaps are no longer available or don’t have ongoing development. With something like Microsoft Word, then it should be possible to obtain the latest version, but naturally that will require a new purchase and/or an annual subscription.

Purchasing a new version of existing software will be an expensive business to just maintain your existing functionality

Maintenance Decisions

The standard maintenance advice for computers is to upgrade to the latest available version of operating software; that way, security patches are up-to-date, keeping the system secure, with new functionality as well as bug fixes provided, and support for the latest applications.

On this occasion however, it is worth taking a long considered look at the benefits of upgrading verses sticking with your current macOS release. If you haven’t yet moved to macOS High Sierra 10.13.4 or macOS Mojave 10.14 then you may wish to stay where you are for now, particularly if you’re happy with your current applications and functionality, such as Microsoft Word 2008. If you’re contemplating upgrading, either because you ‘must’ for security purposes or need to support a new generation application, then it will be worth taking the time now to review all of your existing software and work out what the upgrade path will be, or find out what the alternatives you could migrate to e.g. Apple’s ‘Pages’ to replace Microsoft Word, etc.

The most worrying situation will be for owners of specific hardware e.g. the M-Audio USB Midi interface, which may not (and never will) have a suitable updated driver software alternative

In such circumstances of uncertain application support, backups are as always essential; ideally you should be in a position to ‘roll-back’, dual-boot and/or run virtual machines to maintain previous applications and functionality. 

Consideration should also be given to maintaining a dedicated computer at the existing macOS version, and over time, migrating day-to-day applications (where they can be) to a new computer, keeping the old machine for ‘legacy support’.

Further Assistance

Take a look at the full Apple announcement about the transition to 64-bit technology and how it affects 32-bit apps.

@YellowsBestLtd satisfies new and ‘legacy’ requirements for the maintenance of systems and networks by providing services, such as technical assistance and hardware repairs, and solutions, including the supply of spare part items and software support.

We would be keen to hear from you regarding your operational needs, please get in touch.

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Keymile UMUX – Multiservice access solutions

Comprehensive Functionality

The UMUX platform provides carrier-grade reliable multi-service multiplexing and aggregation functions over copper and fibre networks. A variety of voice (POTS, FSX, FSO, ISDN) and data (e.g. G.703, V.11, V,24, V,35) interfaces, SHDSL and Ethernet (including PoE+ and EoS) services are available. 

The modular and flexible housing provided by the UMUX 1500 (8U, 21-slot) and UMUX 1200 (4U, 8-slot) 19” subracks provide the perfect solution for all applications and locations, offering redundant controller and power supplies.

‘Legacy’ telecoms history

The UMUX SDH product portfolio was originally launched 1991 by Ascom, which subsequently became Keymile.

In 2003, by when 70,000 units had been deployed worldwide, the ‘enhanced’ UMUX multiservice access platform was introduced, offering the delivery of ATM, TDM and IP based services from the same platform, with support for IP/Ethernet, ADSL, VoDSL and G.SHDL.

Keymile was sold to ABB in 2017 when the UMUX range was discontinued, and then was acquired in 2019 by DZS. 

Continuing to provide operational service

The UMUX, together with the UNEM network management system and ‘sister’ LINERUNNER and MILEGATE products, continues to provide operational service with various global Operator, Utilities and Transport companies. 

@YellowsBestLtd supports requirements to maintain these networks by supplying various spare part items from refurbished and surplus stocks in perfect working order.  

There follows a list of the main elements that are typically provided, though other items can be provided. Please let us know of any specific requirements you may have. We look forward to being of assistance.

Part CodeUnit typeDescription
A31A1679U1500-CSU1500 Core R2 (DC) for 19″ mounting (incl. Subrack, POSUM, COBUX 128x2Mb/s XC)
A30A0205DATAS-FUData Interface unit.  Multi-Interface V.35, V.24/V.28, X.24/V.11, RS485, Ethernet, 4 ports, all options
A24A3323LOMIF-FU2 Mb/s IF (E1), 8 x G.703 Interfaces
A24A3651COBUX-FUControl Unit Standard,128x2Mb/s XC
A21A2865EXLAN342POTS FxO Interface Unit, 12 ports, complex impedance
A31A7871GECOD371Data IF 64kb/s G.703 codir., 8 interfaces
A24A3338LOMI4-FU2 Mb/s IF (E1), 4 x G.703 Interfaces
A24A7979POSUM306Power supply unit -48VDC 85W
A30A1442SUBH3-FUPOTS FxS  Interface Unit, 30 ports
A31A7873SULIS393ISDN Interface Unit Subscriber side, ISDN BA 2B1Q, 8 interfaces
A23A9927SYNAC-FUSDH Access bridging unit SBUS-PBUS, 8xVC-12; no external IF
A24A1989TUPON-FUOptical Trunk Interface 8Mbit/s 1xopt.(o), 4xel.(e), 1550nm, PBUS access


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PC Troubleshooting Project

Stop Code: PROCESS1 INITIALIZATION FAILED

As a result of a PC replacement and upgrade project for Action for Asperger’s, we were presented with a seemingly serviceable Dell Optiplex 755 machine but suffering from a critical failure on power-up, meaning that the computer was unable to boot into windows, preventing use and severely limiting the diagnostics and configuration options.

PC restart

The first step following a reboot was an automatic ‘startup repair’, however, this didn’t result in a fix:

Startup Repair

Rebooting again and selecting F2 during the initial boot-up screen:

Boot Up

enabled a look at the system information, which indicated that the PC hardware was fine.

System info
Processor info
Memory info

As an extra measure, the internals of the computer were briefly examined, ‘reseating’ components including the video board, memory chips and hard disk and then the system test run to verify all was well.

Internal
Test

It was concluded therefore that the PC hardware was not the cause of the difficulties, and that the Windows installation was severely compromised. 

From the bootup, troubleshooting was selected

Choose an option

From the ‘advanced options’, the Command Prompt was accessed.

Advanced options

Using these commands:

DISKPART

SEL DISK 0

LIST VOL

It was possible to view and confirm the drives and their assigned letters.

Diskpart

Extra information was provided using this command:

wmic logicaldisk list brief

Progress was further hampered by the internal DVD/CD drive not being recognised on boot-up, in its place an external DVD drive was connected.

Rebooting and pressing F12 on power up enabled the adjustment of the Boot priority, selecting the DVD drive first.

A copy of the Boot Repair Tool by yannubuntu was next downloaded and a boot-repair-disk created

This was run from boot and gave encouraging results:

Boot Repair Disk

Alas, these steps hadn’t cured the problems, now a further critical error message was displayed:

Recovery

Consequently, using the Microsoft USB/DVD Download Tool, a Windows 10 install disk was created (confusingly the site specifies Windows 7, but it works fine for Windows 10)

This was booted and the appropriate selections made for a fresh installation of Windows 10:

Windows Setup
Windows Install now
Windows type of installation
Windows operating system selection
Activate Windows
Applicable notices and licence terms
Partition choice

At this point, it was found necessary to delete the old windows partition, extend a different partition and create a new partition in order to be able to commence the windows installation.

Partition selection

It did however then allow the installation of Windows onto the other partition, meaning that two bootable volumes were created. Might be useful for future upgrades or troubleshooting.

Choose OS

Just the straightforward matter left of completing the user configuration of the operating system ready for use. 

Choose region

All done, pleasing to conclude that the critical issues with this PC could be resolved through software corrections alone! 

@YellowsBestLtd provides professional Management Services for Business Development activities and Enterprise Support of Infrastructure. We source Solutions for Sustainable Systems maintenance, equipment Technologies and telecoms and other Products to enhance operations.

We’re always keen provide whatever is needed, so please let us know anything you require.

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Launch of Telecoms Products

Management Services and Solutions

@YellowsBestLtd provides professional Management Services for Business Development activities and Enterprise Support of Infrastructure. We source Solutions for Sustainable Systems maintenance.

Together with our broad range of new and ‘legacy’ equipment Technologies, we have now launched a portfolio of telecoms Products, enabling Customers to do more whilst reaping cost-benefits. 

Below is listed the Market Sectors of our Customers, together with the equipment Technologies and telecoms Products we can supply.

We’re always keen to expand our portfolio, so please let us know anything you require as we can usually provide whatever is needed.

Market Sectors

  • Maintenance Companies
  • Private Networks & SMEs
  • Public Safety (Police, Fire, Ambulance)
  • Systems Integrators
  • Telecoms (Carriers, Operators)
  • Transport (Rail, Metros, Underground, Highways, Aerospace)
  • Utilities (Electricity, Gas, Oil, Water)

Equipment Technologies

  • Optical Fibre and Copper, PDH Access & SDH Transmission, Telecommunications equipment
  • TDMoIP, Pseudo-wire, IP Data and Voice Telephony
  • Carrier Ethernet, C / DWDM optical fiber multiplexing technology
  • Microwave Radio, wireless coverage solutions
  • Private Mobile Radio (PMR), TETRA infrastructure, terminals, accessories
  • CCTV Cameras, security systems
  • LED displays and information signs
  • Antennas and Radio Direction Finding (RDF)
  • Solar Energy off-grid installations
  • Power supplies and peripheral devices
  • IT network, workstation, server, storage products
  • Network Management Systems (NMS), OSS software
  • Test Equipment

Telecoms Products

  • Telephone Lines & Calls
  • Connectivity Voice & Data
  • Hosted Cloud Telephony
  • Telephone Payment Line
  • PBX
  • Call Centre solutions
  • Dialler Service
  • Reports & Statistics
  • Cost Centre Billing
  • Conference Calls
  • 03 & 08 Numbers
  • Voice and Omni Hub
  • Marketing & Inbound numbers
  • VOIP & IP PBX / Cloud Telephony
  • ADSL & Internet connections
  • SMS Text messaging & survey
  • Fax and other servcies
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Happy New Year

Best wishes for 2019 to all our Customers and suppliers from @YellowsBestLtd.

We hope we can be in touch again soon to understand requirements and discuss how we can work together for mutual business benefit.

Looking forward to being of further assistance in an exciting year ahead!  

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Nokia ‘Dynanet’ Telecoms – Stock disposal

‘Last chance’ for spares!

The Nokia ‘Dynanet’ family of PDH Transmission telecoms products has served customers well for the last 20+ years, and indeed some networks continue providing good operational service. 

DM2
Dynanet Subtrack

@YellowsBestLtd has supported requirements to maintain these networks by supplying various spare part items from refurbished and surplus stocks in perfectly working order.

However, demand has recently reduced and warehouse space is needed, so now the time has come to recycle / dispose of a large proportion of the remaining equipment. Consequently, there remains a short-term opportunity to obtain any items still required to maintain existing deployed infrastructure, before the products are gone.

Here is a stock list of the main items currently available, though there may be a few additional parts that can be supplied. Hence, please check and if you do have any requirements, please let us know – before it’s too late! We look forward to hearing from you.

Part  NumberDescription
24204TPSO H/W Module
CC 24002DB2 Branching Unit, B2 2×2 Mb/s 75 ohm
CC 24011DB2 2 Mb/s Switching Unit, X2 75 ohm
CC 24101DN2 Interface Unit (IU2) 2×2 Mb/s 75 ohm
CC 24111DN2 Control Unit (CU) 75 ohm
CF 24186DN2 19″ Subrack
CF 24186.09DN2 Subrack 19″, grey-L91 EMC
CG 24170DN2 Bus Power Unit (BPU)
CG 24171Extended DN2 Bus Power Unit (EBPU)
CU 24013Data Interface Unit (DIU) 2M, nx64k: G.703/704, 75 ohm
T30506.0917-slot DYNANET Subrack
T30851.02Subrack Power Adapter (SPA)
T37870.01NDM ACM2 19in 17-slot subrack
T37871.01NDM DN2 19″ 17-Slot Subrack
T37882.01NDM DC Unit (NDUe)
T37882.02NDM DC Unit (NDUe)
T37885.01NDM Ring Generator
T37889.01NDM Backup Unit (NBU)
T65520.01ACL2 RM DC Power Gen
T65580.01ACL2i PF GEN Line Terminal Card
TA 21513Optical Line Terminal Repeater 2-8 M, 1300 nm LED MM/SM
TA 21516Optical Line Terminal Repeater 2-8 M, 1300 nm LASER SM
TC 21101DM34 Mux Card
TC 21301DM8 Multiplex Equipment, 75 ohm
TC 21705Supervisory Substation
TC 21710.01TMS Adapter
TG 21261Ring Generator 25HZ 15W
TU 21122.5Data Interface Unit (DIU) 48..64k V.11 10ch
TU 21124Data Interface Unit (DIU) NX64k V.11/V.35/X.21 2CH
TU 21124.05Data Interface Unit (DIU)
TU 21125Data Interface Unit (DIU) 48..64k with sync, X.21
TU 21205Channel Unit SUB/SUB
TU 21206Channel Unit SUB/SUB
TU 21215Channel Unit SUB/EXCH
TU 21216Channel Unit SUB/EXCH
TU 21234.20Channel Unit E&M/VF-P, 10 CH, 20 E&M CH
TU 21236.10Channel Unit (CU) 8ch E&M/uP: 2xe&m/vf
TU 21255.01Channel Switch, 4 PORT
TV 21640.08Power Interface Adapter DC
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Three years milestone

Three years completed; onward in our fourth year!

@YellowsBestLtd has now reached the significant milestone of completing three years of trading; something often useful to be able to state when qualifying for opportunities and registering with business customers.

Our aim continues to be “Keeping Customers Operational”; understanding requirements and fulfilling them by providing a range of management services and solutions, including:

  • consultancy, such as business development planning3_years_services
  • technical support, e.g. day-rate engineering, NMS assistance
  • systems supply, including legacy IT servers / workstations
  • spares for infrastructure, in particular telecoms and CCTV cameras
  • repairs at module and component level, e.g. LED displayboards
  • value recovery through reverse logistics, resale and recycling

As we move forward in year four, we’d very much like to discover what else to provide to our existing Customers, as well as what would be of interest to potential clients. We’re always keen to enhance our range of #business services, increase the #enterprise infrastructure we support and expand our mix of #sustainable solutions we offer for supply and maintenance of new and legacy #technologies and products.

Please get in touch to discuss your challenges; whether you’re implementing new systems or maintaining existing infrastructure to serve your operational business needs. We look forward to hearing from you.

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Solar energy project

“Off-grid eCharger”

The aim of this ‘off-grid’ solar energy project was to build a charger for an eBike so that its battery could be charged (when not in use) from power collected from the sun via a ‘fixed’ off-grid installation, rather than relying on mains energy. This can also be used for other battery charging and small backup supply purposes.

Four main elements were put together to create the solar charging ‘system’:

SolarPorjectElements

Solar Panel

This fundamental part performs the key task of converting sunlight into electrical energy. There is a wide range of panel types to choose between. Firstly, sizes include the very small, through 50W, 60W, 80W and up to 100W. Thereafter, systems are typically built from connecting multiple panels together.

Solar Panel

50W Mono Flexi Solar Panel

Then, there are four main types of solar array:

a) Poly Crystalline – cheaper to manufacture, sensitive to high temperature, less efficient with a shorter lifespan
b) Mono Crystalline – more expensive, more efficient, with a longer lifespanc)
c) Thin-Film Amorphous (A-Si) – flexible, lower cost – easier to produce, shorter lifespan, lower power
d) Concentrated PV Cell (CVP) – very high performance, solar tracking and cooling required, very expensive.

Finally, there is the choice of construction type:

i) Rigid – cheapest and most solid, heavy and longest lasting
ii) Flexible – PET – light-weight and bendy, ideal for vehicles and temporary installations
iii) Flexible – ETFE – longer lasting, marine grade, can be walked on.

For this project, the aim was to use something lightweight that could be easily attached to an existing small building structure by means of the re-enforced ringlets in its corners (not all panels have these, so choosing had to be careful), rather than a permanent roof-top installation, and so the Flexible PET type was indicated.

After some consideration of likely ‘sun-hours’ – estimates tend to indicate an average of 2-3, depending on the season and weather – and also cost, a 50W 12V Mono Crystalline Flexible PET panel was selected. This size could prove to be an under-estimation for the task, but this can be supplemented later as necessary since its possible to join panels in parallel to increase current (or series, to increase voltage). That will require ‘T’ or ‘Y’ joining pieces for the MC-4 solar cable connectors, and potentially in-line fuses to protect separate ‘strings’ of connected panels (on their own they don’t need the fuses since their short-circuit current rating is sufficient).

If a panel becomes partly shaded, its whole output diminishes. Hence the advantage of having separate panels is that they may contribute more energy individually that using one large single panel. Another aspect is that it is likely that the cost of solar panels will reduce over time, and so adding to the system over time makes sense, rather than trying to ‘future proof’ the power requirement.

;

Charge Controller

The task performed by this element is to ‘condition’ the output of the solar capture, converting an unregulated supply of around 18V (for a single panel) to a more stable 12V, the energy from which can be directly used or stored in the battery. The use of a controller avoids the risk of over-charging of the battery or issues with varying power, and will shut off its output to the loads when the supply is diminished and the battery is discharged. There are many models, which vary in power rating and functionality, some with simple LED displays and others showing a range of information, and may include sense terminals for long cable runs, temperature measurement for adjustment due to the weather and equalisation functionality for spreading charge across multi-battery systems.

PWM Charge Controller

PWM Charge Controller

The controllers fall into two main types:

a) PWM – Pulse Width Modulation

b) MPPT – Maximum Power Point Tracking

The latter of these is much more efficient, likely to convert more of the captured solar energy into stored power. However, these tend to be at least 3 times more expensive, often much more.

A modestly–priced (reasonably-functioned) PWM unit was selected for this system, with a 20A rating (more than enough for the initial project requirements). The reasoning for this product selection is this: with a small system, should the captured energy be not enough, then purchasing additional panel(s) to increased the wattage is more cost-effective in terms of energy produced, compared with the gain from the more efficient controller. It only becomes worth purchasing the MPPT version when much more energy is being generated (and therefore ’lost’ with a less efficient charge controller).The controller model selected is capable of both 12V and 24V operation, which allows for the increase the voltage rating of the system if desired in the future.

;

Battery

The traditional choice for this type of storage application is the ‘Lead-Acid Cell’, though it needs to be of a Deep-Cycle ‘Leisure’ variety, which is intended to be frequently discharged and recharged, rather than the ‘starting’ classification which is used in a vehicle for short-bursts of energy to get a motor running, after which its mainly in stand-by and therefore expected to be 100% charged most of the time.

AGM Battery

AGM Battery

Apart from this distinction, there are two main types of product:

a) ‘Flooded’ Wet-Cell or Valve Regulated Lead-Acid (VRLA)

b) Absorbed Glass Mat (AGM) or Gelled Electrolyte (Gel)

Of these, the Wet-Cell traditionally required periodic ‘maintenance’, topping up with fluid, though VRLA sealed versions are now available, and tend to ‘vent’ gas and can’t be tipped over due to the fluid inside. The AGM and Gel types however are available maintenance-free, don’t ‘vent’ gases and don’t have fluid that can spill out.

The AGM-type was selected for this project as, whilst being a bit more expensive, offered the convenience of a product shouldn’t require special attention; these are less sensitive to over-charging and can stand for 30 days totally discharged without harm.

There are a number of measurements of the capacity and capability of batteries:

  • Reserve Capacity (RC) is how long the battery can deliver a constant current of 25A at 80F
  • AmpHour (AH / C20) represents how much charge is stored. It is the energy delivered continuously in 20 hours at 80F without falling below 10.5V
  • Cold Cranking Amps (CCA) is a measure of the ability to start an engine cold. It is the number of Amps delivered at 0F for 30sec by a 12V battery whilst maintaining at least 7.2 Volts

A capacity of 110AmH was chosen for this project.  Whilst ‘the more the merrier’ in terms of storage is certainly the case, this capacity should be sufficient for the basic storage needs.  It is advisable however to allow for discharge of only 50% of the stated rating, whilst also bearing in mind the possibility of a few days without sun.

It is possible to add batteries in Parallel to create more storage, or in Series to increase the voltage of the system. For a modest system set-up, 12V is sufficient and convenient for the purpose. Adding another battery to double the system voltage to 24V would have a side-benefit of requiring lower gauge of wiring.

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Inverter

In order to convert the 12V DC power generated from the Solar Panel and stored in the battery, to the 240V AC required by the Load, the Li-Ion battery charger adapter, an inverter is needed. This wouldn’t be the case if a suitable 12V charger-adapter could be sourced, which would avoid the inefficient ‘double-conversion’ of 12V DC into 240V AC and back into 42V DC again. The inverter does however provide the flexibility for powering other equipment requiring an AC ‘mains’ supply and therefore is ideal for a range of charging and backup tasks.

PSW Inverter

PSW Inverter

Apart from the selecting the correct voltage, which is normally either 12V or 24V (12V required to fit with this system set-up), there are two main choices:

a) Modified Sine-Wave

b) Pure Sine-Wave

The first type is the low-cost product, and available in a wide range of power-ratings, so if high-power is required then that tends to be the preferred choice. The draw-back is that it is less-efficient, creating a ‘blocky’ AC waveform which can upset sensitive equipment. The second type produces a smooth sinusoidal AC waveform equivalent to the standard AC ‘mains’ supply, and therefore is suitable for all equipment types, though at higher cost and usually lower-power rating.

Given the performance uncertainty and potential for harm to some equipment that the MSW product might bring, and the modest power needed, it seemed sensible to select the PSW variant. A 300W product was chosen, partly limited by cost, but also since it is recommended to ‘match’ the power rating to the consumption requirements; in practice the inverter size should be around 3-7 times the power needed by the load appliance. A much higher-than needed inverter is ultimately less efficient for smaller loads, consuming more power than necessary.

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Additional parts required were cabling and mounting accessories, plus some optional ‘add-ons’ in the form of other battery chargers and lights to make full use of the generated power:

System accessories

Accessories

Accessories – MC-4 Connectors & Cable, Light, Battery Charger, Fuses and holder

  • An extension cable to connect the solar panel to the solar controller. The panel itself comes with about 1m of ‘tails’, fitted with MC-4 connectors which are standard for solar equipment. A ‘male’ connector provides the positive supply, and a ‘female’ connector offers the return negative connection. Two cables are therefore required, with the appropriate MC-4 connectors at one end, and unterminated at the other to connect to the solar controller. A ‘top tip’ is to obtain a single fully-terminated extension cable of twice the required length, and cut the cable half-way. For this project, a 25m extension cable was sourced, which provided 12.5m as a sufficient length for both positive and negative connections once cut in half. Thickness of the cable is an important consideration, so that the rating is sufficient for the power of the system and the loss due to the length of the connection. For this installation, a 4mm2 (12AWG) cable was selected, suitable for up to around 15m and 23A, meeting the needs.
  • Battery terminal leads
  • Midi and Blade Fuses and holders for fusing of the output from the battery supply (40A) and protecting the input to the charger controller (15A). The inverter came with a 35A mini-blade input fuse.
  • Lugs and wire for the Solar supply and DC power connections
  • Fixing screws for the solar panel, and cable clips
  • 12V Lamp with remote and motion sensor, providing a light powered by the solar energy for the indoor work area
  • AA / AAA / C / D / PP3 battery charger, for supplementary battery charging requirements, fed from the 12V output from the charge controller (avoiding unnecessary 240V conversion)

The resultant assembly captures energy from the sun via the solar panel, ‘conditioned’ by the controller (to avoid over-charging or issues with varying power) and stored in the battery. Naturally, this can take place throughout the day when the sun shines, without the need for a load to be present. Then when required, the load can be supplied from the stored energy.

The inverter is utilised to supply a replacement AC feed to the specialised Li-ion charger required for the load battery, which can therefore be used as an ‘off-grid’ power source for other uses in place of a regular ‘mains’ supply.

Charging additional Li-ion or Ni-Cad batteries for other equipment can be also be facilitated using the 12V output to supply an appropriate battery charger, and as well as powering 12V LED lights for illumination of the work space.

Hopefully this project is of interest and of use to anyone contemplating establishing a solar energy system, with the aim of harvesting energy from the sun, a ‘free’ resource available to us all!

@YellowsBestLtd our mission is in “Keeping Customers Operational”. We’re always keen to enhance our range of #business services, widen our #enterprise infrastructure support  and expand our mix of #sustainable solutions we offer for supply and maintenance of new and legacy #technologies and products for our customers.

Please help us understand what would be of interest to you by getting in touch to discuss your management services or solutions requirements, whether you’re implementing new systems or maintaining existing infrastructure to serve your operational business needs. We look forward to hearing from you.

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