[KISS]

Interesting article on motor starting currents with plots and easily understandable, I think:

Induction Motor Control

[KISS]

On page 12, here: http://ecatalog.squared.com/pubs/Mot...8910CT9301.pdf

Try to locate the wire connected to (95) and try to locate L1 ( The one without Wire B)

(95) goes to the relay coil. We are interested in the other side. A terminal nearby without a wire connected. It's probably the spade terminal at the top without a wire connected to it.

[Larry T]

I believe it is on the top left. There are two open terminals there.
What do I connect there ? Is that where the pressure switch wires in to for powering up the coil ?
Do I run power into L 1 on the pressure switch, and then out from T 1 to the open spade connector ? Then when the switch opens it removes the power from the coil ?

[KISS]

I need a picture.

[Larry T]

Okay, something is not right here. I have voltage at each of the spade connectors at the top by the lines in. Is that normal ?
Also, when I push in the red button it really doesn't seem to push anything, but there is a mechanism that if you take a screwdriver it will push in like a contact. Should this be this way or is there something missing ? In your picture, I see your blue wire going from L 1 , but where is it going to ? I cannot find the connector it should go to.

[Larry T]

Ok, I guess the big problem here is where is the coil ?
I looked up a picture of a replacement coil and I am not finding it on this starter. Do I need to remove something to get to it ? I think that is where I am missing my connection. Is it at the top behind the contactor or is it at the bottom under the push button ?
I see on the picture there are two connectors on the coil but I cannot find either one. Obviously they are under something, or I am missing the coil ?

Thanks !

[KISS]

OK, from the picture there should be a couple of big terminals where your power is connected. Then there will be corresponding big terminals where your motor is connected.

From the starter pictures, at the top, behind the big terminals, there should be a couple of small terminals. See if you can locate these. One should already have a small wire attached to it. One should not. They are likely spade terminals from the catalog page. Just see if you can find them.

The button on the front, will do NOTHING. It only resets an overload, so, quit playing with it.

[Larry T]

Yes, those I have located. The spade connectors behind both of the lines. There are three on each side. Two running front to back of the box and then one on each side behind those running side to side. On the right ( facing the switch ) the front right has a wire. On the left the single rear spade has a wire. Both wires run to the bottom in connectors inside a clear housing. When I test voltage all of the spade connectors even the empty ones show 117 volts.
Should they ? Are these the coil connectors ? Do I power into one of them if it already shows voltage ? I am kind of confused with this.
I will stop pushing the red button now.

[KISS]

I have to wait until I can annotate some pictures before I take this further.

The 120 your seeing is perfectly fine if your measuring it with respect to ground. As an example, if you connect a 120 light bulb to one side of the 240 and measure either side of the light bulb with respect to ground, you'll get 120 and the light bulb will be off.

[KISS]

OK, Larry. Simple question:

I posted a picture of a starter. It's not yours, but it's clearer. I labeled the terminals of interest 1,2,3 and 4.

Can you tell me what terminals have a small gauge wire attached to it or if it's not representative of your starter. There should be two of them with small wires.

[Larry T]

Hey, I got it to work. It started up great ! But... I think I need a different pressure switch. It ran great and shut down well. I drained off some air to get it to kick back on and it was a little much. It must have a hard time starting with that much pressure. SO I drained off some more to about 75 lbs. and it started fine again. The switch I have now s a 150 lb. cutout and I believe a 110 restart. I am not sure if this switch is adjustable like the last one. I do not believe so but I will check it out.
It is a Square D with 4 connectors.

Thanks for all the help!!

Larry

[KISS]

Make sure you didn't use terminals 1 and 2 directly, otherwise the overloads won't work.

[Larry T]

What do you mean ?

[KISS]

In my pic, a contact closure from 1,4 is OK (might work)
A contact closure from 2,3 OK (might work)

1,2 NO; 3-4: No

3 to 1 and 4-2; No (overloads bypassed)
1-3 and 2-1 No; (Overloads bypassed)

This assembly is not to be thought of as a relay, but a contact closure (overloads) in series with a relay coil.

[Larry T]

I went 2 - 3. Seems to work fine other than the pressure switch setting. I think from what I read that I have a range from 70 - 150 lbs. I need to turn the nut counter clockwise to reduce.
I think it should be pretty straight forward.

Thanks!!

[KISS]

Larry:

Glad you have a handle on things now. I was getting worried. See you AMHD PM's on the main page (unrelated).

You could consider creating an "unloader" for your compressor, if it doesn't support one. You could get more life out of the compressor.

The unloader could be created by an accumulator (small tank), check valve, a 3-way valve, aux contacts on your starter and a controlled orifice.

The idea would be that the compressor operates into the accumulator + a 3-way vent valve and a check valve.
Through ab aux contact the vent would activate when the compressor was off.

This would remove about a displacement's worth of air when the compressor stopped. Thus, the compressor would never operate under a large load and the heads of the compressor would never be pressurized, except during operation.

Think about it.