Pumps and Relays

[astormatt]

Hi all

I am working on a job and I am having trouble getting my head around it. Normal systems are fine but this is causing me a headache.
It is an S plan with an additional pump so both the DHW and CH have a pump and a valve, I know that the pumps have to be split due to it back feeding but I am not sure where to insert the relay in the circuit and what and where do i need to connect A1 and A2.
Ths is my first time doing a boiler system with relays for pumps so struggling with the working out of it. My initial thought was to use the motor connections in the valves (brown) to go across A1+A2 which would them allow me to split the oranges and pumps but the oranges still need to be connected together to send the switch line back to boiler to get it to fire....
Amy help would be appreciated as I think the wet pants are realising that I don't know how to connect it all up!!


Matt

 

[Leesparkykent]

Hi all



I am working on a job and I am having trouble getting my head around it. Normal systems are fine but this is causing me a headache.

It is an S plan with an additional pump so both the DHW and CH have a pump and a valve, I know that the pumps have to be split due to it back feeding but I am not sure where to insert the relay in the circuit and what and where do i need to connect A1 and A2.

Ths is my first time doing a boiler system with relays for pumps so struggling with the working out of it. My initial thought was to use the motor connections in the valves (brown) to go across A1+A2 which would them allow me to split the oranges and pumps but the oranges still need to be connected together to send the switch line back to boiler to get it to fire....

Amy help would be appreciated as I think the wet pants are realising that I don't know how to connect it all up!!





Matt

Does the boiler have pump over run? A1 and A2 are the coil connections.

 

[davesparks]

You need one relay for each pump, but also need to ensure that the pump overrun works correctly so you need to work with the plumbers on that one to establish which pump will be hydraulically connected to the bypass or if a third pump will be used for the overrun.

All relays will come with a diagram of what each pin does.

If you can't work it out in your head then draw it out.

 

[astormatt]

Thanks sort he input so far, there is an internal pump in the boiler (vaillant) and a low loss header installed so I am guessing that the internal pump just pumps around that.
Sorry Lee, I know that A1 and A2 are for the coil but I am struggling to think about what needs to be connected across it to energise it.
I only turned up to help a mate do a bit of second fixing and have had this dropped on me....
I will try draw it out, it is probably one of those things which is simple once I have worked it out.

 

[davesparks]

Might have been an idea to mention the ll header in the OP!
With that kind of system you may have the valves operating the respective pumps only and the boiler maintaining the low loss header temperature independent of those valves through a temperature sensor fitted to it.

You need information from the person who designed the system in order to wire the controls correctly for the design.

 

[Lucien Nunes]

Wot he said.

But let's suppose you have the boiler's internal pump, and a pump for each circuit that is valve controlled. In principle you make the programmer and stats open the valves as usual, but instead of taking the orange valve outputs to a common point to control the boiler, each one feeds the pump for that circuit and a relay. I.e. one relay per valve, with coil terminals A1 and A2 in parallel with the pump so the relay energises with the pump when its valve is open. The N/O contacts on all the relays are paralleled up and used to switch PL to the boiler SL, so that when any valve is open, its relay fires the boiler.

 

[Leesparkykent]

The cylinder charging pump and ntc senor for the low loss header will normaly connect direct to the boiler in a vaillant boiler.

 

[davesparks]

Wot he said.

But let's suppose you have the boiler's internal pump, and a pump for each circuit that is valve controlled. In principle you make the programmer and stats open the valves as usual, but instead of taking the orange valve outputs to a common point to control the boiler, each one feeds the pump for that circuit and a relay. I.e. one relay per valve, with coil terminals A1 and A2 in parallel with the pump so the relay energises with the pump when its valve is open. The N/O contacts on all the relays are paralleled up and used to switch PL to the boiler SL, so that when any valve is open, its relay fires the boiler.

Not necessarily, some low loss header systems maintain the header at a constant temperature then each zone valve just operates the associated pump.

But then without the designers information we're all just ****ing in the wind!