Sterling 32a auto crossover switch issue (tripping RCD)

[EuroTrotters]

Hi,

can anyone help please ?.

I installed a Sterling 32a crossover switching unit. Switches automatically between Shore (EHU), generator or Inverter.

All was well, but it meant I had to re-wire the fridge and battery chargers to it’s own MCB. Meaning I had to manually switch off fridge (AES) and internal battery chargers when on inverter.

It was always my intention to fit the Sterling CON1 relay to the auto crossover. Which I Have. But now, when selecting EHU or generator . Everything trips !.

I have attached a wiring diagram from Sterling (can you spot any error ?).

And I have wired the Con1 exactly as per the diagram (though upper row 1,2,3 13 differs by number).

can anyone shed any light in this please ?

 

[autorouter]

In the wiring diagram of the contactor, there is an inconsistency between the upper and lower diagrams. I think in the lower diagram the connection L2, labelled Neutral In, should be Live In. Similarly L3, labelled Live In, should be Neutral In. That would make it consistent with the upper diagram.

In your photos I can't see which wires go to the L2 and L3 'ring main in' connections, but I suppose you could have switched them depending on which diagram you were following at the time. That could be the cause of your tripping problem.

 

[EuroTrotters]

Thank you.

that was the error I discovered. Made things worse when switched to the lower diagram.

but it’s wired as the upper version again.

problem I have now is. Even with the contacted/relay disconnected. Back to the original wiring through the 32a switchover, it instantly trips on all sources now!. .

I will have to get my mega out and see what’s gone wrong

 

[autorouter]

problem I have now is. Even with the contacted/relay disconnected. Back to the original wiring through the 32a switchover, it instantly trips on all sources now!. .

I will have to get my mega out and see what’s gone wrong

Yes, back to square 1 I think. Disconnect everything, then connect one thing at a time, testing every time.

 

[EuroTrotters]

Yes, back to square 1 I think. Disconnect everything, then connect one thing at a time, testing every time.

I’m just wondering if something has gone wrong with the auto changeover . I’ll update later

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[EuroTrotters]

Okay, so the reason for tripping was two loose cables shorting in the garage. I must have disturbed them.

The Con1 relay still does not operate. So I am awaiting an exchange. It arrived damaged anyway. But it was only the din rail clip as far as I could see. That’s not used with the supplied box.

 

[autorouter]

If you connect live to A1 and neutral to A2, the contactor should click on, and you should see resistance between L1 and 2T1 (blue letters) go from infinite to very low (ie continuity). Similarly between L2 and 4T2, and between L3 and 6T3. Also between 13NO and 14NO. That's the relay section at the top, not the overload cutout below, also labelled the same but not in blue.

If that's OK you could then see if there's continuity between the (blue) 2T1 terminal and the (white) 2T1 terminal which is the output of the overload cutout. If no continuity, maybe the wiring problem you describe managed to trip the overload cutout. I don't know if this type of cutout automatically resets or whether there's some procedure for resetting it. I can't see the manual for this device, there;s some kind of glitch on the Sterling website.

In fact it might be better to check the cutout first, it's likely that it's triggered and needs resetting.

 

[EuroTrotters]

If you connect live to A1 and neutral to A2, the contactor should click on, and you should see resistance between L1 and 2T1 (blue letters) go from infinite to very low (ie continuity). Similarly between L2 and 4T2, and between L3 and 6T3. Also between 13NO and 14NO. That's the relay section at the top, not the overload cutout below, also labelled the same but not in blue.

If that's OK you could then see if there's continuity between the (blue) 2T1 terminal and the (white) 2T1 terminal which is the output of the overload cutout. If no continuity, maybe the wiring problem you describe managed to trip the overload cutout. I don't know if this type of cutout automatically resets or whether there's some procedure for resetting it. I can't see the manual for this device, there;s some kind of glitch on the Sterling website.

In fact it might be better to check the cutout first, it's likely that it's triggered and needs resetting.

I will try that tomorrow!.

I’m confused by sterling’s instructions. It states the signal to the relay/contacter is low power

 

[autorouter]

A relay or contactor is an electrically operated switch. Heavy-duty switch contacts are controlled by a low-power 'signal' current which flows through a coil. The coil is an electromagnet, the signal current causes the magnetism that pulls the heavy-duty contacts closed.

What Sterling are saying is that the 'Battery Charger Disengage Signal' (labelled F on the Autocrossover switch diagram) is intended to switch a low-power signal to the coil of a relay/contactor (that's the A1 and A2 terminals). It's the heavy-duty contacts of the relay/contactor that switch the high -power current to the battery charger and fridge. These are the L1 & T1, L2& T2, L3 and T3 contacts, although you are only using two of the three pairs.

So the wires to the Battery Charger Disengage Signal terminals, the A1 & A2 terminals and the 95 and 96 terminals of the overload cutout relay can be quite thin because they are not carrying the load current, they are carrying only the signal current.

 

[EuroTrotters]

A relay or contactor is an electrically operated switch. Heavy-duty switch contacts are controlled by a low-power 'signal' current which flows through a coil. The coil is an electromagnet, the signal current causes the magnetism that pulls the heavy-duty contacts closed.

What Sterling are saying is that the 'Battery Charger Disengage Signal' (labelled F on the Autocrossover switch diagram) is intended to switch a low-power signal to the coil of a relay/contactor (that's the A1 and A2 terminals). It's the heavy-duty contacts of the relay/contactor that switch the high -power current to the battery charger and fridge. These are the L1 & T1, L2& T2, L3 and T3 contacts, although you are only using two of the three pairs.

So the wires to the Battery Charger Disengage Signal terminals, the A1 & A2 terminals and the 95 and 96 terminals of the overload cutout relay can be quite thin because they are not carrying the load current, they are carrying only the signal current.

Yes, I used a contacter for one of my last switch overs. But it was too slow for the victron inverter . I was confusing low power with low voltage !

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[EuroTrotters]

Replacement finally arrived from BMS.

All wired in and now fully automated !

Auto switches from EHU to Generator / Secondary EHU input to Inverter/Charger. The only thing we have to remember to do is. Switch to Charger only on the Inverter when leaving the van unattended with Habitation A/C or Electric heating on. Otherwise, circuits (ring main) will switch to batteries and drain.

 

[donkey]

Hi

Isn't it a bit strange that Sterling refer to the contactor as a 'contractor', it would give me concern that it could be a 'knock-off'.

Geoff

 

[autorouter]

Isn't it a bit strange that Sterling refer to the contactor as a 'contractor', it would give me concern that it could be a 'knock-off'

Not strange at all, unfortunately. I'm sure if I gave a Sterling manual to my old English teacher it would come back covered in red ink.