s-plan diagram for mo mo valves

[D_Hailsham]

A Sunvic 'Motor Open - Motor Closed' valve is wired exactly the same as a 'Motor open - Spring Closed' valve. If it's a two port valve there is no need for a wire from the programmer CH 'Off' or HW 'Off'. Any switching is done internally to the valve.

Check out the Patent Application.

 

[bolshy]

 

[denso13]

Is there an echo in here

 

[D_Hailsham]

The Sunvic MoMo valve uses mains voltage on the brown wire to open the valve and on the grey wire to close the valve. This means that a MoMo valve cannot be used on a volt-free boilers unless you use a relay to isolate the mains voltage on grey/orange from the boiler's volt-free connections.

 

[matt1e]

The Sunvic MoMo valve uses mains voltage on the brown wire to open the valve and on the grey wire to close the valve. This means that a MoMo valve cannot be used on a volt-free boilers unless you use a relay to isolate the mains voltage on grey/orange from the boiler's volt-free connections.

Yup agreed
I think it is the mid position momos that are a direct replacement for their spring return counterparts

Matt

 

[thyristor44]

Going to try a quote

 

[thyristor44]

If I operate the valve directly from the timer it would stay open when called for. The boiler would be controlled from the relay and I could take the output from the mo-mo valves internal switch, through the thermostat to control the relay.
Would that be alright.

nope
The problem is that if the hotwater is in demand then the boiler will be firing and the pump will be running
If the system is wired as you suggest then the central heating thermostat is overridden on every time the hotwater is in demand

Matt

I see your point.
I have two mo-mo valves, one for dhw and the other for c.heating. Does that improve things.
Each mo-mo has its own channel from the timer and the switch in each mo-mo goes to its own thermostat and from there to the relay which switches on the pump and boiler.
Much easier if I could draw it for you.

Read more: //www.diynot.com/forums/plumbi...mo-valves.359477/page-2#2717803#ixzz2OTX4Nw00

 

[matt1e]

Much easier if I could draw it for you.

No need, take it from me it won't work
I'll try to explain
Both your actuators switch on the boiler and pump . Ok?
Both valves open and let heated water through to either heat the rads or hot water as req ..ok?
Both valves have to be able to close to stop any more heat getting through when req as the heating may be up to temp whereas the cylinder is not for example
The respective stats control the opening and shutting of their respective valves to achieve this
The boiler and pump need to run when ever there is a demand so either valve actuator will do this

Logically it is like this
System
Demand = open valve
No demand = close valve

Boiler
Any valve open = boiler demand
No valve open = no boiler demand

Capiche?

 

[thyristor44]

Thats a bit of a blow. Back to the drawing board. I may be back but thanks for help anyway.