View single post by jlagrua
 Posted: Thu Jun 22nd, 2006 07:50 am
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Joined: Wed Jun 21st, 2006
Posts: 4
Okay, while I do see the odd penny in the sump, the gremlin lies elsewhere. I pulled P5 off the motor control board and measured resistances:

(Recirc to Neutral) Red/Blu to White 20.3 Ω (Spec is 10-12Ω)
(Drain to Neutral) Tan/Yel to White 20.3Ω (Spec is 10-12Ω)
(Recirc to Drain) Red/Blu to Tan/Yel 40.6Ω (Spec is 20-25Ω)

While this appears out of spec, keep in mind this is an aftermarket pump/pump motor.

So, I got out the trusty ShopVac and purged it yet again, put it into its very familiar prostrate position and pulled off the bottomplate to have a look at the "knickers".

I pulled the plug from the pump motor and measured again - Identical readings.

Okay, so the wiring is good, and without proper spec sheets, I'm gonna call the motor good for the moment.

So, I get adventureous- I pull off the impeller cover to the pump (as this aftermarket pump is WAY more serviceable than the stock POS). All is clean, and all is spinning freely. No grinding, no spindle slap, no noise at all.

So here's the rub- I go into the now all too familiar manual Diagnostics mode and turn on the pump in recirc mode, and dive down for a look-see. Impeller spinning away happily. Turn off recirc, pump stops. Good so far. Next I put pump into drain mode. Nada, nichts, zero, zilch, bupkis, big freakin gooseeggs.

So now to apply- if the resistances of the motor windings are symmetrical -

(Follow me here) The ratio for the windings is:

(Recirc to Neutral) vs (Drain to Neutral) 1:1
(Recirc to Neutral) vs (Recirc to Drain) 1:2
(Drain to Neutral) vs (Recirc to Drain) 1:2

Then the ratios are identical to the ratios for the factory pump (rememeber the factory specs):

10-12Ω, 10-12Ω, and 20-25Ω (10x2=20 and 12*2=24)
Hence 1:1, 1:1, and 1:2.

Ergo, more evidence the pump is okay, spec-wise. So, if the pump is good and I'm getting voltage in recirc but not drain, and we have established the wiring is good, that tells me that no magic blue smoke is getting to the pump from the board.

So here's the $149.00 question: what voltages should I be getting at P5 of the Motor control Board for each pair of pins (recirc-neut & drain-neut)?

I pulled the board and visual inspection yeilded no burnt components or solder joints. I decided to give the pins a test and here's the voltages:

Tan/Yel to White (Drain) | Off: 188-190 mVAC | Recirc: 184mVAC | Drain: 153-154VAC
Red/Blu to White (Recirc) | Off: 184 mVAC | Recirc: 119.9-120.2VAC| Drain: 205-207mVAC

Now call me crazy (or Ishmael), but while 120VAC seems acceptable for a voltage to run an AC motor running off house current 153-154VAC does not. However, without a schematic of the board and specs, as well as specs of the motor, I can't say for sure where the fault lies. If it were the motor I would expect to see resistances MUCH different than what I'm seeing. Also, I would not suspect a motor to die in 7 days under very light usage (and without the accompanying burnt electrical stink). Perhaps the capacitor on the motor assembly? Again without specs, I can't say for sure. Any ideas? I still want to say motor board, but I'd rather PAY for the capacitor. Or returning the pump/motor for a exchange for free is good too, but it just doesn't fit.

Any info appreciated.