Square D Contactor... need urgent help!

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Greg Swartz

Greg Swartz

Senior Member
Location
Colorado Springs, Colorado
Well, we went over that. We went over the wiring from L1, through the NC stop, through the NO start in parallel with the contact for the coil, through the coil, to L2...

We'll check that out tomorrow... it's quite dark, and behind a wall... daylight is our friend, not flashlights and 480... (I know... what kind of electrician do you call yourself...)
 
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emahler

Senior Member
by the time they figure this out, this thread will be longer than any ground up/down thread on this site:D
 
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bjp_ne_elec

Senior Member
Location
Southern NH
Greg Swartz said:
Ok, new contactor / coil combo is in...

Actually needed the new overload too...

So, push the start button, it engages... let go, it disengages.

Keep in mind we are only dealing with the factory start / stop buttons. The other ones are disconnected right now.

contactor is receiving 480V... like it needs.
Click to expand...

So did you verify, as hillbilly1 had suggested, that there was an issue with the auxiliary contact. Consistent with that schematic i sent you, these contacts should close, and are in parralel with the Start switch. So when you let go of the Start switch, the contact being closed, has essentially taken over for the momentary close of the Start switch - thus applying full control voltage to the coil.
 
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hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I failed to mention though, If you add a remote pushbutton station, you will need to add a fuse to protect the control circuit, when the control is self contained to the starter, it is allowed to be fused at full starter amperage, but when the control wiring leaves the enclosure, it must be protected at the ampacity of the control wire.
 
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bjp_ne_elec

Senior Member
Location
Southern NH
hillbilly1 said:
I failed to mention though, If you add a remote pushbutton station, you will need to add a fuse to protect the control circuit, when the control is self contained to the starter, it is allowed to be fused at full starter amperage, but when the control wiring leaves the enclosure, it must be protected at the ampacity of the control wire.
Click to expand...

Great point!
 
Greg Swartz

Greg Swartz

Senior Member
Location
Colorado Springs, Colorado
hillbilly1 said:
I failed to mention though, If you add a remote pushbutton station, you will need to add a fuse to protect the control circuit, when the control is self contained to the starter, it is allowed to be fused at full starter amperage, but when the control wiring leaves the enclosure, it must be protected at the ampacity of the control wire.
Click to expand...

bjp_ne_elec said:
Great point!
Click to expand...

I hate those great points!
 
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jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Greg Swartz said:
Well,
The Start / Stop buttons are at line voltage. The L1, 277V goes directly through the NC Stop and the NO Start... to the coil...
The coil voltage is 480V.
Click to expand...
I'm still confused.
The coil is 480V, but you say you are only feeding it with 277V. Is the stop button connected to L1 and the overload relay contact to L2?

If your control circuit does not included a grounded conductor, you should not be using ground (or neutral) as a reference point when making voltage measurements.
 
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hardworkingstiff

Senior Member
Location
Wilmington, NC
hillbilly1 said:
I failed to mention though, If you add a remote pushbutton station, you will need to add a fuse to protect the control circuit, when the control is self contained to the starter, it is allowed to be fused at full starter amperage, but when the control wiring leaves the enclosure, it must be protected at the ampacity of the control wire.
Click to expand...

Could you use #14 wire and Table 430.72(B) column C and skip the separate overcurrent device? Looks like 14 could be protected by the branch circuit overcurrent device. I assumed 45-amps (Column C for #14)would suffice since the contactor was 30-amp rated per the OP.
 
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