Building Control Issue

[stevie gill]

We've just installed a new 3-phase PV system onto a rebuilt community centre, where the pan is to bring in a new 3-phase supply. The new supply has been delayed, and the clients want to get the building up and running.

We can easily use a single phase conversion kit in the DB to provide power to all other services, but they have stated the Building Control officer won't sign of the building until the PV has been commissioned!

We have a three phase SMA inverter and 1 single string of panels, meaning that it's nigh on impossible to amend the wiring and opt for single phase inverters at this stage.

Am I right in thinking that there's literally nothing we can do to get the system commissioned and MCS certification generated?

Thanks in advance

 

[TedM]

Does the design need the PV to meet Part L? How many kWp and what make/model are the panels?

 

[stevie gill]

Does the design need the PV to meet Part L? How many kWp and what make/model are the panels?

Yes, our PV and an air source heat pump were both a big part of the planning process, and are required (just a shame the main contractor didn't think that he'd have to give WPD lots of notice to bring the new supply in!)

We have an SMA STP5000TL-20 inverter powering 1 single string of 18No LG300w B3 Neons. The route from the inverter/mains position up onto the roof is virtually inaccessible now - I did look into the feasibility of installing 3 single phase inverters as an option before posting.

 

[BruceB]

If time critical then, temporarily fit the smallest single phase inverter that will take that number of panels, commission, then swap inverter later.

 

[stevie gill]

If time critical then, temporarily fit the smallest single phase inverter that will take that number of panels, commission, then swap inverter later.

That's just it, I'm struggling to find a single phase inverter that'll handle that loading (5.49kWp). Any assistance would be appreciated.

 

[BruceB]

I thiink a few will take the power (SMA & ABB) but not the voltage as a single string. Perhaps run some temp cables from the roof externally to split string into two?

 

[stevie gill]

I thiink a few will take the power (SMA & ABB) but not the voltage as a single string. Perhaps run some temp cables from the roof externally to split string into two?

That was my findings too. The idea of having to re-attend and get additional cables onto the roof at this stage, with no access equipment on site, is bringing me to tears.... and all this just as a temporary measure! We'd then have to return again and re-instate the 3-phase setup. Madness

 

[Gavin A]

stecagrid SG3600 will do that voltage single string

 

[whinmoor]

How about a Fronius Primo 3.6 ?

 

[SibertSolar]

Does it have to be a <16A/G83 inverter?

 

[stevie gill]

Does it have to be a <16A/G83 inverter?

Yes it does.

 

[BruceB]

Looks like both those suggestions would work. The theoretical maximum power is a bit high but that will not be an issue until the spring by which time you can have swapped to 3 phase.