CH won't come on - motorised valve problem?

[seco services]

If all the wires are live the valve should have motored to CH

it will still motor if only the white is live but only to mid position.

if it hasn't motored you shouldn't get power on the orange

you'll still get power on the orange if the motor hasn't moved providing there is 230v on the grey the orange will have only about 100v.

 

[twgas]

If all the wires are live the valve should have motored to CH

it will still motor if only the white is live but only to mid position.

So it wont have gone to CH (ok I should have said ONLY, or port B closed

if it hasn't motored you shouldn't get power on the orange

you'll still get power on the orange if the motor hasn't moved providing there is 230v on the grey the orange will have only about 100v.

agreed, but I did mean mains power (240v ish)

I only miss these small details to confuse people

 

[seco services]

i'm not trying to say you where wrong.
just adding extra to what you had stated.

 

[twgas]

Fair enough, Seco, it's easy to overlook the little bits of descriptions that we take for granted

 

[illshaw]

Thanks for the replies guys. I've got around to looking at this again today and I've found that the problem is the microswitch that powers the motor - yes I know I should have checked this properly first time!. As it is US then I broke it open and the contacts between white and motor was burnt out. I've managed to scrounge a PCB for actuator from a mate's old valve and this fits. However when the valve moves to A/B mid position, it oscillates to and fro with the microswitches clicking. I don't recall this happening before and thought that the DC was supposed to stall the motor stationery. Is the clicking etc right or are the switches not aligned properly.

 

[MANDATE]

There are two simultaneous voltages applied over the first half.
(a) 240v direct through microswitch (1) and also
(b) The lower rectified voltage, this comes from microswitch (2) and the small pcb, but this feeds the motor after the microswitch.

When actuator reaches mid position microswitch (1) is triggered.
It now depends whether or not the grey wire is 'live'. If the grey is not live, there is no 240v to power the motor further.The original 240v (a) above is dropped, so you are just left with lower rectified voltage to hold the actuator against the return spring.

It's only when the grey wire is live that the motor continues when microswitch (2) is triggered. This drops the lower voltage (no longer required) and redirects the 240v from the pcb to the orange wire.
Based on this there should not be any oscillation involving microswitch (2)

Sounds more like the rectified voltage is not strong enough when microswitch (1) is triggered. contacts white to motor open and grey to motor close. actuator drops back. contacts close and open again. the 240v from white is reinstated and starts the whole sequence over again.

 

[illshaw]

Thanks. I did have to move the spring a little to fit the new PCB and is it possible that the spring is now too strong for the rectified DC? Therefore it return to A and then triggers SW1 again to power the motor and so on.