How to write an hour meter?

[PT Doc]

How to wire an hour meter?

I'd like to put an analog hour meter on my compressor. Something like this:
This one is 8-80v.
http://www.harborfreight.com/hour-meter-66754.html

Here is one from grainger that is 230v:

http://www.grainger.com/Grainger/ENM-Hour-Meter-2PAR1?Pid=search

How would this be wired into the compressor wiring? I would guess that one would want to only count the hours that that motor/pump are running.

My compressor is 230v 5hp 1 ph. It will be wired to the 6 50 receptacle via 6/3 SOO cord.

Thanks for any help.

 

[rwhite692]

You only need a 110V hour meter. Wire it up to the pressure switch (which should be using one leg (110V) and the hour meter will only run when the pressure switch is calling for the motor to run.

 

[luvit]

hey.
my hour meters jump 1/10th of an hour each time power is applied as a power-on test.
would this 1/10 extra hour throw you off each time the compressor kicks on?

 

[PT Doc]

hey.
my hour meters jump 1/10th of an hour each time power is applied as a power-on test.
would this 1/10 extra hour throw you off each time the compressor kicks on?

That would be plenty fine. I just want measure of run time and I would rather it over estimate than under estimate.

 

[PT Doc]

You only need a 110V hour meter. Wire it up to the pressure switch (which should be using one leg (110V) and the hour meter will only run when the pressure switch is calling for the motor to run.

Since 1 leg is 120v, would the harbor freight meter work in this application since it is 8 to 80v?

 

[TWX]

Since 1 leg is 120v, would the harbor freight meter work in this application since it is 8 to 80v?

That will depend if it can handle the amperage running through it, or if not, if there's a neutral. My 240V compressor doesn't have or use neutral.

 

[nehog]

You only need a 110V hour meter. Wire it up to the pressure switch (which should be using one leg (110V) and the hour meter will only run when the pressure switch is calling for the motor to run.

He's running a 240 volt compressor, so a 110 volt hour meter won't work unless it is wired to neutral (if it exists!) and one leg of the motor. Done properly he needs either a 240 to 120 dropping transformer (or 240 to 48 volt for the Harbor Freight unit...) or an hour meter that meets the power specifications for the compressor's motor.

Since 1 leg is 120v, would the harbor freight meter work in this application since it is 8 to 80v?

No, that won't work. 80 volts is much less than 120. About 34% more, actually, so you'd quickly let out the magic smoke.

You can use a transformer as mentioned above.

 

[Charles (in GA)]

They used to make, I assume they still do, vibration operated hour meters. Hard mount one to the motor or pump and it will operate while the shaking is going on.

Otherwise you need a 240v meter wired across the coil operating terminals of the magnetic starter. Usually the coil has one hot supplying it directly and the other hot comes thru the pressure switch to the coil, thus when the coil is energized with 240v the meter will also. Or you could wire across the two hot outputs of the mag starter going to the motor.

Charles

Charles

 

[Stuart in MN]

Grainger has a 230vac hourmeter for $24. http://www.grainger.com/Grainger/ENM-Hour-Meter-2PAX3?

 

[Mattlt]

They used to make, I assume they still do, vibration operated hour meters. Hard mount one to the motor or pump and it will operate while the shaking is going on.

. . .
Charles

Charles

I had never heard of these. Bunch of them on ebay for < $20. Learned something today - thanks.

 

[rwhite692]

He's running a 240 volt compressor, so a 110 volt hour meter won't work unless it is wired to neutral (if it exists!) and one leg of the motor. Done properly he needs either a 240 to 120 dropping transformer (or 240 to 48 volt for the Harbor Freight unit...) or an hour meter that meets the power specifications for the compressor's motor.

What I was talking about, is if he (like me) is using a motor starter/contactor which uses a 110V coil to drive the contacts which switch in the 220V main power, which is driven by the pressure switch (which just uses one, 110V leg). It may not apply, though, if he isn't using a starter/contactor.

at to that Harbor Freight meter (8 to 80V) I believe that is a DC meter intended for typical 12V DC systems on things like forklifts or other types of power equipment.

 

[nehog]

What I was talking about, is if he (like me) is using a motor starter/contactor which uses a 110V coil to drive the contacts which switch in the 220V main power, which is driven by the pressure switch (which just uses one, 110V leg). It may not apply, though, if he isn't using a starter/contactor.

at to that Harbor Freight meter (8 to 80V) I believe that is a DC meter intended for typical 12V DC systems on things like forklifts or other types of power equipment.

I think it is unusual for a 120 volt contactor to be used, certainly my compressor has 240 and no neutral. We don't know about his (which is why I mentioned using neutral, if he had it.) But if you do have a 120 volt contactor then a 120 volt hour meter would work quiet well.

You're correct on the application of that meter. I'd guess most are used on 24 volt systems, and 48 volt ones too. The hour meter on my generator set is 24 volts (it has an 24 volt system, being ex-military)

 

[rwhite692]

I think it is unusual for a 120 volt contactor to be used, certainly my compressor has 240 and no neutral. We don't know about his (which is why I mentioned using neutral, if he had it.) But if you do have a 120 volt contactor then a 120 volt hour meter would work quiet well.

You're correct on the application of that meter. I'd guess most are used on 24 volt systems, and 48 volt ones too. The hour meter on my generator set is 24 volts (it has an 24 volt system, being ex-military)

You are right, what I meant to say, is that my motor starter (Seimens WS5-2301P) has a 220V coil and I use the pressure switch to switch one of the 110V legs on the contactor coil to activate.