Page 1 of 1

Voltage Runaway-No Field Voltage

PostPosted: Mon Jun 04, 2012 2:59 pm
by bhb
At the end of last summer, my 20 year old Next Step regulator had a voltage runaway when we were underway (voltage and current spiked, engine rpm pulled down by alternator drag). I got engine rpm down fast enough to avoid damage. The regulator was indicating a voltage runaway, but no other charging systems were operating. I thought the regulator had failed due to age, so I bought a NS 2 regulator and installed it. I started up the engine and all operated normally. I did not use the boat again until last weekend. On start up the new regulator came on line then dropped off line. The error codes indicated a voltage runaway, even though there were no other charging systems operating. I shut down, turned off all battery power to recycle the regulator, and then restarted - same thing happened. Then I checked the integrity of all connections. Two of the alternator connections were loose and were tightened. Now when I start up I no longer get the voltage runaway code or any other codes from the regulator - no green or red leds, only the middle amber led is lit, and no field voltage. The voltages on TB1 (from pin 8) are as follows (ignition off, ignition on, engine on):
1. 13.02, 13.00, 12.85
2. 0, 0, 0
3. 0, 0, 0
4. 13.02, 12.97, 12.86
5. 0, 12.80, 12.80
6. .17, .17, 17 (T+ disconnected)
7. 0, 0, 0
Is the regulator faulty, or is there another possible explanation?

Re: Voltage Runaway-No Field Voltage

PostPosted: Mon Jun 04, 2012 3:18 pm
by Coulomb
You missed Pin 8 which should be at ground.

Loose alternator connections are very hard on electronic gear because they generate a series of high voltage transients.

The regulator should probably be tested.

Re: Voltage Runaway-No Field Voltage

PostPosted: Mon Jun 04, 2012 5:13 pm
by bhb
Pin 8 is at ground, I didn't list it because everything else is measured from it. I live in Seattle and will bring it in. Is 2442 NW Market Street, #43 the right address for service?

Re: Voltage Runaway-No Field Voltage

PostPosted: Tue Jun 05, 2012 4:39 pm
by Coulomb
That address is our mailing address. You can drop it off there if you want.

Otherwise email Ruth@ ---- to schedule a time she will be in.