Zone Valve (erie type)

Alan(OnVacationInOregon)Forbes

Thanks for taking the time.

Alan

Dave Faust_2

Zone Valve (erie type)

Does the motor in a zone valve keep running or is there some means to stop it once the valve is switched?
Any good troubleshooting or how to sites would be appreciated.
Thanks,

Big Ed

Spring Loaded

All sprng loaded zonevalve and I if I can remember Erie is too, need to be powered to stay open . If not the spings would close the valve...

Power on -power off zone valves(if they still make them like the old Flair) .Needed speical thermostats to control.The used the cooling contact to shut the valve off. These also used 5 wires or in rare cases 4 with a shared common.....

bob_50

The motor

is energized as long as the valve is open. The motor opens the valve against the spring and stalls. The motor is impedance protected ie it can't draw enough current to hurt it's self. I just took out a MH that has been powered open continiously for twenty two years that I know of and it still functioned OK.

rich pickering

Unless

it is a normally open valve and then they tend to stay powered all summer.

Alan(OnVacationInOregon)Forbes

Impedence protected

Bob:

What exactly happens to the power once the valve is fully opened? Normally, a stalled motor overheats. Just curious.

Alan

bob_50

Alan

If you measure the resistance of the primary winding of a transformer you will read X ohms. If you now connect the transformer( say it's a regular 110volt to 24 volt) to 110 and measure the current draw in amps it won't jibe with the resistance measurement you made useing Ohm's law. It will draw less current than you would suspect. The reason is when you coil a wire it causes inductive reactance which acts like additional resistance. This apparent resistance plus the actual ohmic resistance is called impedance. It impeds the flow of current. It's like the flow of water through a strait pipe compared to one that's coiled up. If you design the coil in the motor so that the impedance is high enough it can't draw enough current to make it overheat. A lot of small motors used in refrigeration equipment are impedance protected. Hope this makes sense. bob

Dave Faust_2

Oh!

Thanks for the details! These make it "make sense".

JJ_4

Commercial heating applications

Just a side note: On commercial heating applications we "fail to heat", meaning the spring opens the valve on a loss of power (electricity or air) so that coils don't freeze until the power returns.

For spring return valves, Normally Open means the valve is open when no power, Normally Closed means the valve is closed when no power.

rich pickering

But

Most of the time, the pumps are powered from the same panel, so the valves are open, but there is no flow.

Unless there is a standby generator.

But the pumps are probably not wired to it.


Life is full of buts.