Forget the part in my original post about the 30 VDC output - I had the digital multimeter in the wrong mode. As it looks now, the generator was never really the problem at all. See my status report at the end of this post for details.
Here are replies to several other posts. Thanks to all for your input.
David M: Yes I looked through the troublshooting checklist but it said nothing about loss of output voltage. I have not yet contacted Northern Lights but have talked to an employee of Hatton
Marine in
Seattle, a factory authorized
service center. He told me he was the design
engineer for that generator. More on conversations with him in the status report below.
Kanani: See above for explanation of 30 VDC. I did not change any wiring in the
control box except to disconnect one multiconductor connector and pull one lead off the DC circuit breaker at separate times. The connector only goes together one way so I couldn't have messed that up.
Because I only had only one wire off the circuit breaker at a time, I feel confident I didn't screw that one up either.
Alan: I disconnected the good battery and let the generator run for about an hour to recharge its dedicated Trojan starting battery. Since then it has started the engine several times and seems to be holding its charge quite well.
Quartersplash: The haulout facility in Guaymas uses the 300 ton TravelLift at the shrimp
boat yard across the street until they dredge a channel to their own smaller
lift ways. The
storage yard owner has plans to put in a
ramp to
haul out multi-hulls by
trailer but judging from the rate of progress on dredging, I wouldn't expect to see a
ramp in operation for another year or two. Unfortunately for you, the ways at the shrimp boat yard are only 25 feet wide (I measured with a tape measure before my haul out last spring). The dry storage is semi-secure in that there is a cyclone fence around the yard with a gate that is never locked but is usually swung
closed and occasionally guarded by yard workers. The yard itself is a dirt lot. There are really run down
head and
shower facilities sharing the building in the center of the yard with the office and a tool room. Next to that building are some old
fish oil tanks that appear to be constantly leaking or overflowing. The good news is that
living aboard is permitted and the rates are really low. See their web site (
marinasecaguaymas.com) for more details and pictures.
Current Status:
The
engineer I talked to recommended
cleaning the slip rings under the field excitation
brushes then starting the generator and measuring its output voltage. If it had not built up quickly, I would have had to flash the field as this particular machine has no separate field flash circuitry, contrary to indications in the owner's manual.
Initially I did not want to inspect the slip rings because that end of the generator is only a few inches from the aft end of the engine room and the sound shield on that end of the machine has several hoses and
cables through it that prevent it from being lifted out. Working left handed with a mirror, I was finally able to clean the slip rings until they were shiny again (wish I'd had a rubber arm for that task!).
After starting the machine again, I measured the voltage at the main output terminals with two separate meters on the correct scale this time and saw 242 VAC as expected. Unfortunately, when I closed the main distribution breaker on the output of the generator, voltage dropped instantly to zero. When I reopened the breaker, voltage came back up. I called these results in to the engineer in
Seattle who then informed me that there must be a direct short across the output that causes the field in the generator to collapse.
Tomorrow I'll rip into the distribution breaker to see if there is a smoking gun (or varmint) there. I'll post another follow up with my findings and hopefully final resolution after that phase of the investigation. Meanwhile I'm
charging our house
batteries with
solar panels supplemented by main engine as necessary every few days.