earth rod for TL invertors

josh55 · Apr 7, 2011

Iv been told you need to install a earth rod to earth array when using transformerless invertors ,seems a bit ott rcd not enough ?

1st Solar · Apr 8, 2011

Yes Josh apparently its true, (see the ‘array frame earthing decision tree’, in the DTI guide), but you only need to do this if it’s a PME supply. Use 10mm. Good luck

daytona600 · Apr 8, 2011

class a rcbos for pulsed dc for transformerless TL inverters to stop dc leaking into the grid
as these have no galvanic separation , HF range has transformers fitted but yields are lower
per esc guidelines i have supplied these for over two years now
also plug in grounding kits if hybrid sanyos or thin film panels are used

BruceB · Apr 8, 2011

Why do hybrid Sanyos need a plug in grounding kit?

mmorse60 · Apr 8, 2011

According to the Sanyo Rep in Segens technical conference Sanyo panels dont need a grounding kit

Markc · Apr 8, 2011

1st Solar said:
Yes Josh apparently its true, (see the ‘array frame earthing decision tree’, in the DTI guide), but you only need to do this if it’s a PME supply. Use 10mm. Good luck

Not strictly true. If PME then earth stake array in 10mm earth, If TNS or TT then earth bond array back to MET in this case the size of bond cable must be equal size to bonding conductors already installed to the water, oil, gas etc.

Markc · Apr 8, 2011

daytona600 said:
class a rcbos for pulsed dc for transformerless TL inverters to stop dc leaking into the grid
as these have no galvanic separation , HF range has transformers fitted but yields are lower
per esc guidelines i have supplied these for over two years now
also plug in grounding kits if hybrid sanyos or thin film panels are used

Its a Class B RCD not RCBO. RCBO's are not good practice to protect PV as most are not double pole. Regardless of this the Class B RCD is required to protect TL's from injecting DC into the AC system.

As for the Sanyo's I was told by Sanyo rep that grounding kits are not a requirement.

1st Solar · Apr 9, 2011

Markc said:
Not strictly true. If PME then earth stake array in 10mm earth, If TNS or TT then earth bond array back to MET in this case the size of bond cable must be equal size to bonding conductors already installed to the water, oil, gas etc.

Apologies Josh, missed that bit! Marc C is correct; if it’s PME then stake it and if not then take it back to the CET

josh55 · Apr 11, 2011

1st Solar said:
Yes Josh apparently its true, (see the ‘array frame earthing decision tree’, in the DTI guide), but you only need to do this if it’s a PME supply. Use 10mm. Good luck

Thanks very much ,must read DTI guide more often.

daytona600 · Apr 12, 2011

sanyo hybrid mono and thin film
sanyo recommend grounding but not mandatory
if using transformerless inverters
okay with transformer inverters as they have galvanic isolation
thin film produces much higher voltage than mono or poly
sma and others make inverter grounding kits for sanyo and thin film modules
thin film over produces in voltage for first few weeks up to 12weeks until it settles down
also at low temperatures in strong sunlight as virtual junction temperature is low
esc guidelines recommend pulsed dc rcds/rcbos fitted to inverter outputs to stop dc feeding into the grid

can send data sheets if required

daytona600 · Apr 12, 2011

can email full sanyo data on grounding
not mandatory but recommended by sanyo
esc guidelines on transformless inverters recommend class a not class b rcds

JulianC · Apr 12, 2011

daytona600 said:
esc guidelines on transformless inverters recommend class a not class b rcds

Have a read of reg. 712.411.3.2.1.2

BruceB · Apr 12, 2011

daytona600 said:
esc guidelines on transformless inverters recommend class a not class b rcds

That's not what the version I have says.

Regards
Bruce

[ElectriciansForums.net] earth rod for TL invertors

daytona600 · Apr 12, 2011

so i see bruce this states as you say above
above/esc/bs7671 all different
pv regulations still need to be sorted out in the uk on lots of details
excludes 95% of your competitors with zero electrical knowledge who don,t fit anything at all