Wiring an hourmeter into a start circuit
Wiring an hourmeter into a start circuit
(OP)
I am trying to wire an hourmeter into a 24volt start circuit on a motor. Since the hold in relay does not have an extra set of contacts. I would like to place this in series in the normally closed switch circuit ( the off switch.). The problem I hit was that the current draw of the hourmeter was not enough to keep the relay drawn in.
Would a light bulb work as a shunt or since this is an AC circuit would I be better off connecting a capacator across there. I guess what I am trying to achieve is a parallel circuit which gives the hourmeter enough current to work without starving the relay.
Would a light bulb work as a shunt or since this is an AC circuit would I be better off connecting a capacator across there. I guess what I am trying to achieve is a parallel circuit which gives the hourmeter enough current to work without starving the relay.





RE: Wiring an hourmeter into a start circuit
Gunnar Englund
www.gke.org
RE: Wiring an hourmeter into a start circuit
The hourmeter is, a voltage device it is 3 to 36 volts DC
I had wired a fullwave rectifier to it because the relay is working on 24volts AC.
I will see if I can get at the holding relay to do a parallel connection. This thing is buried under a massive contactor. It was of course much easier to get at the switch wires.
Thank you B.E.
RE: Wiring an hourmeter into a start circuit
Does your fullwave rectifier circuit include a filter capacitor? There are many DC devices (most in fact) that do not like pulsating DC.
Also, a half-wave rectifier might provide a voltage not so close to the upper limit.
Might be cheaper to buy an hour meter that will operate directly from an available voltage.
RE: Wiring an hourmeter into a start circuit
If I do add a capacitor, will I also need a resistor in parallel with it?
B.E.
RE: Wiring an hourmeter into a start circuit
No, the meter itself (being permanently wired in parallel) should be adequate to provide the required parallel load.
If you decide not to use a parallel capacitor to smooth out the pulsating DC, then double check the hour meter to make sure that it is running at the correct speed. Pulsating DC can make things go 'hay-wire' (which is why it should be simply avoided to save time in the long run).
RE: Wiring an hourmeter into a start circuit
I will go back and do battle again with this task today.
If I understand correctly what you are saying, the pulsating DC current may interfere with the crystal oscillator in the timer. Which is why it needs a smoothing condenser.
B.E.
RE: Wiring an hourmeter into a start circuit
Rule of thumb: nothing good ever happens with using pulsating DC power supplies.
RE: Wiring an hourmeter into a start circuit
Thank you for heading me off at the pass before I really screw up.
B.E.