Mystery box of electrics

[andyj301]

The pic shows a bespoke box of electrics, the thick red wire runs from the batteries (left of the pic) to my inverter (right of the pic). When I move the box there is clicking and the inverter turns off and on, slightly alarming is sparking from the black socket on the left, this black cable runs to something called 'drain earth'. A separate, heavier black cable runs from the inverter to something called 'bat earth'. Can someone tell me what this box of electrics is for?

 

[matthewriches]

Looks nasty! Any more photos in situ?

Wants ripping out and throwing away :disgust:

Looks like some sort of disconnect relay.

 

[RichardS]

Is it a heavy duty relay for remotely switching the inverter on and off?

I'm not sure why one would want to do that or why it would operate when you move it unless there is a loose connection .... which could be the black one?

Richard

 

[paulajayne]

The black item is a relay used to switch the battery circuit on.

The smaller wire should be going to the A1 and A2 connections which are the coil.

IF the box is moved and there is clicking then you have a bad connection on the A1 A2 (coil) circuit.
The clicking is the coil becoming magnetised and pulling in the contactors.

 

[andyj301]

Looks nasty! Any more photos in situ?

Wants ripping out and throwing away :disgust:

Looks like some sort of disconnect relay.

Thanks for the super quick reply. I'm trying to simplify the battery system (box is top left with it's lid on). There are twelve SLA batteries in six banks with diodes on each bank.

Think I'll have to do some reading on the make of my inverter to see if it has it's own low voltage cut out, though the surveyor did comment that the electrics were excessively complex.

 

[matthewriches]

Jesus! I think your surveyor was being frugal with his words!

Think that’s a rip it out and start again job!

 

[pvb]

Thanks for the super quick reply. I'm trying to simplify the battery system (box is top left with it's lid on). There are twelve SLA batteries in six banks with diodes on each bank.

Think I'll have to do some reading on the make of my inverter to see if it has it's own low voltage cut out, though the surveyor did comment that the electrics were excessively complex.

What an amazing rats' nest of wiring! It's definitely a start from fresh challenge.

 

[andyj301]

Thanks all for your help.

 

[QBhoy]

Can’t zoom in very well on this phone, but is it a home made split charge relay system ?

 

[William_H]

No if the heavy wires are only for the inverter then it is either a remote switch for power to the inverter or possibly a voltage sensing relay to switch inverter off when batteries get low. (say under 12v). For the first option inverters draw a lot of current so need heavy short wiring from the battery to inverter. The relay may be to enable a small switch at a convenient place to control the inverter by the relay. The second oprion is perhaps not likely as many inverters have a low voltage cut out. Which in itself gives problems because of volt drop in supply cables. The relay of course needs a negative connection to power the coil. A control wire power to which actuates the coil but I can not guess what the heavy black wire is for.
Re the wiring rat nest. Go very slowly on any project to pull it all out. It obviously has apurpose and use you just need patience to sort it out.
good luck olewill

 

[JumbleDuck]

The black item is a relay used to switch the battery circuit on.

In a slightly bodge-y way, as whoever did it has used a three-pole relay to make a single pole one.