Recycling Facility – London

In December 2019, Helios were contacted by a large recycling company in London to assist them with their Ofgem audit. Helios’ usual fee was waived when it became apparent that the company would require our cleaning and maintenance services as well.

With Helios’ wealth of experience in the PV industry, Helios were able to draw upon this experience to acquire documentation that wasn’t available due to the company that installed their system, M3 Solutions, having entered into administration over 2 years previously.

Helios enabled the recycling company to submit all the necessary responses to Ofgem in the required timeframe and identified that there had been an additional 8 panels installed – that shouldn’t have been there.

In addition to Ofgem’s questions being answered, examples of the documentation submitted to Ofgem included:

• Revised single line diagram (SLD)
• Grid Connection Agreement
• Proof of commissioning
• Calibration certificates
• DC Test Sheets

In January 2020 Helios carried out the testing and maintenance of the electrical aspect of the system.

What we found shocked us.

Helios were aware that the system was underperforming by approximately 40% and upon closer inspection, we found out why.

5 of the inverters weren’t working due to ground faults and 3 more inverters could not be tested safely due to the lack of string isolation at the inverters. The active ground faults posed a high fire and electric shock risk.

Incorrect installation practices had resulted in multiple panels being loose and at risk of blowing off the roof in high winds. Mid clamps had been used as end-clamps and vice-versa in a variety of locations resulting in a poor fix to the roof.

Panels had been installed over roof lights and some panels had buckled and cracked due to the thermal stress on the panels.

Almost every visible MC4 connector had not been tightened correctly, likely due to torque spanners not being used to tighten them up, thereby not ensuring a water tight seal on any of the connections. Several MC4’s showed signs of DC leakage into the surrounding area and two had blown apart leaving live DC wiring exposed.

As the list of problems wracked up, Helios enlisted the help of the UK’s most senior PV technician, James Hoare CEng FIET FEI of LHW Partnership, to carry out some advanced string testing to enable Helios to identify where along the individual strings the problems with the connections may have been located.

Following this testing it was recommended to the client that all of the MC4 connections at the end of the strings be replaced, well over 650 different connections, with SunClix connectors. Using the more expensive SunClix connectors would allow Helios to safely replace the faulty DC connectors in a more robust and safe fashion.

Until the DC connectors can be replaced and the system is working correctly Helios will not risk cleaning the panels due to the high risk of electric shock.

How long would you risk leaving your solar panel array in this dangerous condition?

It’s been 6 months for this recycling company.

If you’d like to get your PV system thoroughly tested and inspected and operating at maximum efficiency, contact Helios today on 01525 632238 to discuss your company’s requirements and how Helios can help you today.