"Ebodski" wrote in message
...
I was lead to believe on Ed Sirett's post that the microswitch stopped the
motor ( i.e. tripped something that stopped supplying power to the
motor ).


If the motor doesn't get power then the spring return closes it.


You're inferring that the switch does something else and the motor is
permanently energised as long as my water+heat switch is toggled. So does
this mean that throught winter, the motor is energized as long as the
heating is switched on. I thought a permanently energized motor which
wasn't rotating would just consume power and eventually burn out..


These motors are designed to work in this fashion. They do eventually burn
out, but it can take many years.



Okay, then back to the drawing board with my wiring sketch :-

http://freespace.virgin.net/ian.jarvo/wires.jpg

I've confirmed the '?' wire is the HW tank thermosat.

This will call for hot water from the boiler, but when timer/programmer is
set to call for heating and hot water, this 'stat will be over riden by the
switched live from the motoried valve. That's according to your wiring
diagram anyway.


If the microswitch does not de-energise the synchron motor, then the only
way I can read this wiring sketch is that when the motor is energised by
the
W+H switch, the motor should turn to open the valve ...( this still
confuses
me as I've still got it in my head that the quadrant is closing the
valve )
.If I try to trace the locic of the wires in my sketch, then it seems the
black wire becomes live and this energizes the pump & GCV.



Power is taken from the timer/programmer to the valve motor which begins to
turn the cog wheel in the valve. When the pre-set limit is reached on the
cog wheel a little tag presses the micro-switch and switches a Live supply
to another appliance in the system. So only one of the wires to the
micro-switch will have a constant Live supply which is then switched by the
micro-switch to turn something else in the system on. It can be used to
turn on a relay, a pump, another valve, the gas flow valve in the boiler,
etc. etc. etc.