RCD/RVD combo switch

[oldtrack123]

Hi Terry
Can you check the surge current supplied by the inverter, on air con start up
The inverter digital read out will be too slow,I believe', but you could give it a try, really a job for a fast analogue amp meter
It could be that the RVD's MCBO is tripping simply on the Surge current, not the RVD on a voltage leak
What is the claimed surge current capacity of the inverter?[4000W]

The inverter it self does not temporarily shut down& then reset??? for just a minute or so??

Did a quick search but cannot find much in the way of a manual

I think Ian would be more interested in having a happy customer ,who is in a position to support the product
Try your luck


ps at the week end help son finish his grid tie solar installation, new meter installed ,now on line but had some interesting problems of the unit tripping out due to over voltage
I have mentioned in another place about our consistently high mains voltage[254V]

This,combined with line impedance,lead to the inverter seeing a line voltage in excess of 265V [the safety shut down point]
Just had Energex out,they reduced the mains voltage to 240V but cannot go any lower due to need to maintain voltage at the end of the line
Still having the occasional shut down when the sun is bright

Going to put in some oversized cables between inverter a mains input to switchboard to gain some points of a volt[expect about [0.5V]
But it seems the problem is more in the street mains, & the number of solar set ups in the area all feeding back

Peter

[T1 Terry]

the problem with the combo switch is not when on the inverter, they work together fine without a problem and handles the air con compressor cycling without any problems. The problem is when the mains are plugged in, the inverter switches to bypass and turns it's charger circuit on and takes it's bit, the circuit then goes to the combo switch, all is fine till the air con is switched on, the combo drops out imediately. If the mains are switched off so the air con starts up under inverter power everything is fine, then if the mains are switched on the inverter goes into bypass and the combo switch will remain on. I still don't know if the combo switch drops out when the compressor cycles when on mains power.

For a cheap inverter/charger it is quite amazing just how much over load it will handle, it doesn't shut down, it just screams for mercy the output voltage holds up but if left for too long the 150 amp fuse at the battery finally lets go. The batteries hold their voltage fine, 150 amps is like nothing to them. The fuse size could be increased but it would just move the problem into the inverter. It has already blown all it's internal fuses once on an accidental overload and it's a real piece of work getting it out of it's enclosure to change the fuses.

[oldtrack123]

the problem with the combo switch is not when on the inverter, they work together fine without a problem and handles the air con compressor cycling without any problems. The problem is when the mains are plugged in, the inverter switches to bypass and turns it's charger circuit on and takes it's bit, the circuit then goes to the combo switch, all is fine till the air con is switched on, the combo drops out imediately. If the mains are switched off so the air con starts up under inverter power everything is fine, then if the mains are switched on the inverter goes into bypass and the combo switch will remain on. I still don't know if the combo switch drops out when the compressor cycles when on mains power.

For a cheap inverter/charger it is quite amazing just how much over load it will handle, it doesn't shut down, it just screams for mercy the output voltage holds up but if left for too long the 150 amp fuse at the battery finally lets go. The batteries hold their voltage fine, 150 amps is like nothing to them. The fuse size could be increased but it would just move the problem into the inverter. It has already blown all it's internal fuses once on an accidental overload and it's a real piece of work getting it out of it's enclosure to change the fuses.

Hi Terry
I'll have to digest & dissect that one a bit to See what I can make of it


Peter

[supersparky]

the problem with the combo switch is not when on the inverter, they work together fine without a problem and handles the air con compressor cycling without any problems. The problem is when the mains are plugged in, the inverter switches to bypass and turns it's charger circuit on and takes it's bit, the circuit then goes to the combo switch, all is fine till the air con is switched on, the combo drops out imediately. If the mains are switched off so the air con starts up under inverter power everything is fine, then if the mains are switched on the inverter goes into bypass and the combo switch will remain on. I still don't know if the combo switch drops out when the compressor cycles when on mains power..............................

T1, If I am ready this correctly, the combo only trips when the airco starts AND the inverter is off load and acting as a charger. If that is the case it may be a slight milliamp leakage in one of the inverter charger PCB's and a similar slight leakage in the airco. How accurate are your AC tong ammeters?

[T1 Terry]

The combo switch is after the inverter but before the air con, could the inverter still effect the switch even if it's before it?

The chain of protection is, house supply RCD, RCD on the bus inlet, inverter/charger, combo RCD, RCD for each heavy load such as air con, water heater, powerpoints. The combo switch is the only one that drops out and only when on mains power. If the charger section of the inverter could be the problem I'll check to see if the charger can be turned off, would that then eliminate the inverter from the possible suspects or could it still be creating a problem?

T1 Terry

[oldtrack123]

The combo switch is after the inverter but before the air con, could the inverter still effect the switch even if it's before it?

The chain of protection is, house supply RCD, RCD on the bus inlet, inverter/charger, combo RCD, RCD for each heavy load such as air con, water heater, powerpoints. The combo switch is the only one that drops out and only when on mains power. If the charger section of the inverter could be the problem I'll check to see if the charger can be turned off, would that then eliminate the inverter from the possible suspects or could it still be creating a problem?

T1 Terry

Hi Terry
It still comes down to a double fault situation
#1 fault to set the RVD as a RCD
#2 Fault to earth to trip the mcbo

Has An earth to neutral link be made within the van or the inverter??
From your description does the inverter supply the mains 240V or is it manual switched

If so how has the Earth to neutral bond been made

I cannot locate any manual for THAT inverter/charger & the specs do not give much detail
Do you have one?

Have you checked the actual opereration of all the down stream RCDs
with a tester [NOT THE TEST BUTTON]???

One way to clear the inverter as a possibility would be to by pass the inverter & feed mains direct the the RVD combo making sure you have correct polarity


it is possible you have those TWO faults that some claim can never occur, but it could be some incompatabilty /wiring problem
[Full point to point wiring diagram possible??]
Multiple earth neutrals ,within the system ,can cause problems.

Although just looking at it in block form, it would still seem to be the two fault situation or an over sensitive RVD.
Do you have a sensitive , 50milliamp AC meter

Peter

[T1 Terry]

Hi Peter,
If there were up stream earth neutral links the house RCD would trip, or the RCD at the bus entry point, so I think that eliminates an earth/neutral fixed fault being within the bus. The inverter itself makes no earth/neutral connection, the inverter is a UPS type so switches between mains only or inverter only so no mixed supply possible.
The other bits will have to be left to an electrician further down the line, the vehicle is no longer here for me to test anything. The combo switch trips before any of the RCD's trip when circuit testing.
I think the combo switch is just too sensitive. A job for later, the vehicle very rarely connects to mains power and only the air con produces a trip of the combo switch when on mains on compressor start up and the air con will run for hrs from the batteries if needed so it's not a huge issue, more an inconvenience.
I will contact Ian (Powerstream) and arrange to have the units I have here modified if required and then swap it over the next time I see him, then I can send the switch giving the problems to Ian for testing and modification if that is what the problem is.
Thanks Peter and David for your help.

T1 Terry