What are these relays in the fuse box?

[boris1]

Hello, can someone explain to me what these are and how they work?
I suspect these are relays that control the electro heaters because the heating dials have an On and Night setting. Or because there is a dial in another part of the house where I assume some kind of schedule can be programmed.
There are just three heater circuits (with their own individual switch) but a a bunch of these relays. Why do you need so many?
Another strange to me occurrence is when I screw a fuse in that is wired to these relays, the heaters are turned off. When I unscrew the fuse (10amp), the heaters are on according to the three black dials.
I'd like to learn about relays if not this specific fuse that seems to be counter-productive.

 

[Pete999]

Hello, can someone explain to me what these are and how they work?
I suspect these are relays that control the electro heaters because the heating dials have an On and Night setting. Or because there is a dial in another part of the house where I assume some kind of schedule can be programmed.
There are just three heater circuits (with their own individual switch) but a a bunch of these relays. Why do you need so many?
Another strange to me occurrence is when I screw a fuse in that is wired to these relays, the heaters are turned off. When I unscrew the fuse (10amp), the heaters are on according to the three black dials.
I'd like to learn about relays if not this specific fuse that seems to be counter-productive.

Have you asked the Electrician supervising your work? or are you, like lots of Trainees just thrown in at the deep end and left to work things out for yourself, when I first started work 100% of my time was spent chasing with a 2 lb lump hammer and a cold chisel, also used as dirt cheap labour, that was until the firm went bust and I was transferred under TUPE to a more suitable employer.

 

[Darkwood]

Without more info its a hard call to make, what circuits are marked up on the board?
Possibly lighting contactors so multiply circuits or high loads can be brought in on a small amp rated switch.

 

[Lucien Nunes]

There might be only three separately controllable heating zones but there are as many electrical circuits as there are sets of fuses. Each circuit probably has its own contactor (relay) with the possibility of multiple contactors within any one zone under the control of one programmer, but possible again separate thermostats.

The fuses you mention are probably for the control circuits. The controls might be wired to inhibit the heaters, i.e. the heaters go off when the control circuit is active, but default to on when the circuit is dead. Screw in the fuses and look for why the control system is not correctly controlling the heaters.

You give your location as 'Earth' but presumably this installation is in Finland?

 

[camerabloke]

Have you asked the Electrician supervising your work? or are you, like lots of Trainees just thrown in at the deep end and left to work things out for yourself, when I first started work 100% of my time was spent chasing with a 2 lb lump hammer and a cold chisel, also used as dirt cheap labour, that was until the firm went bust and I was transferred under TUPE to a more suitable employer.

Didn’t know you wore a wig

 

[Pete999]

Didn’t know you wore a wig

Oh you are back? be surprised what I wear Mate

 

[boris1]

Have you asked the Electrician supervising your work? or are you, like lots of Trainees just thrown in at the deep end and left to work things out for yourself, when I first started work 100% of my time was spent chasing with a 2 lb lump hammer and a cold chisel, also used as dirt cheap labour, that was until the firm went bust and I was transferred under TUPE to a more suitable employer.

I was thrown in at the deep end. The project didn't specifically require any work done on these so I was just wondering-- it's a confounding setup. I suspect maybe having to return sometime in the future when it's time to upgrade to breakers and something would have to be done about these.

 

[boris1]

There might be only three separately controllable heating zones but there are as many electrical circuits as there are sets of fuses. Each circuit probably has its own contactor (relay) with the possibility of multiple contactors within any one zone under the control of one programmer, but possible again separate thermostats.

The fuses you mention are probably for the control circuits. The controls might be wired to inhibit the heaters, i.e. the heaters go off when the control circuit is active, but default to on when the circuit is dead. Screw in the fuses and look for why the control system is not correctly controlling the heaters.

You give your location as 'Earth' but presumably this installation is in Finland?

There are more relays/contactors under the bottom plates of this main unit

There might be only three separately controllable heating zones but there are as many electrical circuits as there are sets of fuses. Each circuit probably has its own contactor (relay) with the possibility of multiple contactors within any one zone under the control of one programmer, but possible again separate thermostats.

The fuses you mention are probably for the control circuits. The controls might be wired to inhibit the heaters, i.e. the heaters go off when the control circuit is active, but default to on when the circuit is dead. Screw in the fuses and look for why the control system is not correctly controlling the heaters.

You give your location as 'Earth' but presumably this installation is in Finland?

Yes, this is in Finland. There are a few more relays/contactors under the closed panels on this consumer unit and it seems that are all/most connected together for these heating circuits. I just didn't get a picture of it with the whole thing open. I think I will leave it as is for now since it's a bit of an "if it ain't broke don't fix it" situation.