mark vii start relay specs

[JPG]

That voltage surprises me. I assume you measured the voltage at the relay terminals.

Humor me a bit. Have you determined it runs correctly both forward and reverse?

If so, measure the run voltage at terminals T9 and T5 on the power switch. The red tracer and the red motor wires should be attached to them.

I am getting suspicious of it all not connected correctly.

[lahola1]

Yes, I checked volts at the 2, 5 terminals.

Yes, it seems to run fine forward and reverse ever since I got it going approx 1 1/2 yrs ago, however, about a year ago I cutting some wood and it bound the blade up , motor was buzzing/ humming ; It did not trip the circuit and the motor did not restart after I freed the jamb. I got it turned off in a few seconds. Because of that I've always been a little worried about frying this rare motor.

The red wire is on 5; white/red is on9 ; running volts on 5 and 9 on the switch is 267 volts, however, the red wire at the terminal is somewhat bunt and corroded. see pics attached.

[JPG]

In the interest of complete overview, please take a pix of the relay and capacitor wiring. The switch wiring looks ok.(take good care of that switch).

I think the lamp shield may be backwards.

I may have to get my MVII motor detached and measure the start winding running voltage . I am quite surprised it is 267V. Mine has the internal switch.

[lahola1]

Attached are pics of relay and capacitor wiring as per your request.
In case it's not clear on pic; relay terminal 2,black to switch terminal 2.
relay terminal 5,black, to switch, terminal 2.
relay terminal 5, yellow to motor.
relay terminal 6, wt/bk to capacitor.

Correction: wt/b cap wire IS on terminal 1 of relay, not 6. Couldn't read it very good at my viewing angle.

[JPG]

Attached are pics of relay and capacitor wiring as per your request.
In case it's not clear on pic; relay terminal 2,black to switch terminal 2.
relay terminal 5,black, to switch, terminal 2."2" s.b "5"!(what I see and correct)
relay terminal 5, yellow to motor.
relay terminal 6, wt/bk to capacitor."6" s/b "1" as corrected below

Correction: wt/b cap wire IS on terminal 1 of relay, not 6. Couldn't read it very good at my viewing angle.

I am assuming the relay in the pix IS "apr5".

It all looks correct.

I would set the pot to the mark between 180 and 250(205?).Ya done that already!

So I think you are stuck with the apr5 idiosyncracie re short off cycling.

I would try to clean up the bare wires around the terminals
(at least tape em)

The white rogers may be more acceptable. I will add the model # to this post in a few. 90-65 looks best

[lahola1]

Thanks for all the help JPG.

I ordered a Packard PR9065 relay (cross ref same as W-R 90-65).
W-H was obsolete and more expensive and may have been different brand replacement anyway.

I will post my results in the future if I gained anything or not.

[lahola1]

Relay update:
The packard relay I was going to get was unvailable, so I looked online more and found a NOS Mars 19004 (same specs as the White Rodgers 90-65).

Got it yesterday; installed it and it starts AND restarts just fine.

JPG, can't thank you enough.

Two observations:
1. When I pulled the Supco out of my headstock the terminal that the #5 wire connects to was slightly loose; screw wasn't torqued. Don't know if this was affecting my restarts. I didn't feel like reinstalling for more experimentation.
2. I took my ohmmeter and checked the coils on my original(bad) start relay (3000 ohms) and my NOS Mars 19004 relay (5700 ohms).This means nothing to me but I thought it might be useful to you JPG.

Attached is a pic of the Mars relay box.

[JPG]

I am curious re both he original relay and the supco. Any chance of getting my hands on them?

[lahola1]

Yes, no problem. Can you get me your address and i'll mail them to you.
lenny a.

[luggw1]

Then is the yellow wire the lead to the motor start winding? I've procured a Mars 19004 and am unsure which terminals to connect the motor wires to as it appears to be different than the(RBM, I think) relay that came on the AO Smith motor. Terminals 5 and 1 on the original relay are definitely across the coil as I was able to measure 3.2K ohms of resistance across those terminals. What threw me is the black wire running to the switch from terminal 5 (to the terminal that's out of line from the rest).

I just want to make sure I do it right. According the the instructions for the Mars relay, the yellow lead should connect to terminal 2 of the new relay. Then the black wire from the top row, position 2 of the switch looks like it should connect to terminal 5 of the new relay (terminal 2 on the old relay).

Thanks for the clarification.
Bill Lugg