Why would Line #1 of 110 system go down?

[tulsag]

I am currently in Grenada and went to turn on the GenSet this morning to charge the batteries. When I fired her up, only Line #2 voltage and ampmeter LED's lit up. The matching Line #1 meters stayed black. I reset the breakers but nothing changed. My panel has a light that indicates that 220volts is leaving the GenSet and it was lit. I'm fairly decent with 12v electrical but I don't know much about AC systems (means that they have always worked). It is not just a meter problem because the charger (located on Line #1 fails to come on. Strangely, the back-up charger that is on Line #2 does not come on either even though the meters for Line #2 indicate that it has 120volts!

Any clues as to what I should check for? Could it be the Selector Switch (Shore/Off/Generator)?

Mark Powell
Hylas 54

[Scott Berg]

Mark,
This is probably a problem for a professional. You're working with dangerous voltages and a LOT of things could cause a leg to drop. Much depends on the genset (brushless, brushes, etc) and how it's wired (12 pole, 4 pole, etc)

If you aren't familiar with generators I'd have a good electrician take a look...

S

[svlamorocha]

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[svlamorocha]

Originally Posted by tulsag

I am currently in Grenada and went to turn on the GenSet this morning to charge the batteries. When I fired her up, only Line #2 voltage and ampmeter LED's lit up. The matching Line #1 meters stayed black. I reset the breakers but nothing changed. My panel has a light that indicates that 220volts is leaving the GenSet and it was lit. I'm fairly decent with 12v electrical but I don't know much about AC systems (means that they have always worked). It is not just a meter problem because the charger (located on Line #1 fails to come on. Strangely, the back-up charger that is on Line #2 does not come on either even though the meters for Line #2 indicate that it has 120volts!

Any clues as to what I should check for? Could it be the Selector Switch (Shore/Off/Generator)?

On another angle, it is common to see US-market boats in which the panel lights sometimes do not sork reliably because they have live/hot from one circuit and neutral from the other circuit and they mix hot-only breakers with hot-and-neutral breakers. Apparently in the States it is still normal to share neutrals across circuits and use hot-only breakers in some places, which are big no- nos in other countries.

Mark Powell
Hylas 54

Are you sure you meant to write 220 volts?

It will be easier for you to get help if you tell us more about your setup, starting with make/model of genset and a photo of your AC panel.

C

[Sailormantx]

With the generator running, check your voltage at the generator output. This will give you a starting point for troubleshooting: if voltage is OK, the problem is somewhere in your electrical system, if it is not then it will be something in the generator. Do be careful, working with tools around running machinery and high voltage can be lethal if you touch something or drop a tool in the wrong place!!

[skipmac]

WARNING: AC electricity is dangerous and can kill you. If you are not familiar with standard safety procedures for working around 120/240 V AC then you should hire a pro.

First some questions.

1. Is this a US type power system IE 120/240 V 60 Hz? From your comments I think this is the case but if it is 240V 50 Hz European system the details are very different.

2. Do you have a decent volt meter and know how to use it?

3. Are you familiar with US 60 Hz AC power?

Assuming yes to 1 & 2 and no to 3 then

- US 60 Hz AC has 4 wires: two hot wires of 120V each (lets call them A and B), one neutral wire and one safety ground wire.

- 120V comes from A to neutral or B to neutral which I think in your system is line #1 and line #2

- 240 V comes from A to B.

Examples (simplified versions)
- you have a 120V battery charger you would connect A and neutral or B and neutral to the charger.
- you have a 240V air conditioner you connect A and B to the air con.

The way to diagnose electrical problems is to start at one end and work step by step down the line until you find the problem.

So, you say the panel shows 220 V leaving the generator? Check that with the volt meter. 120V A to neutral, 120V B to neutral and 240 V A to B.

If you confirm this then follow the wiring step by step, testing for proper voltage at each step.

WARNING 2: If this post is not completely clear to you then you need to think about hiring an electrician.

[exkma367]

My troubleshooting practice for bad connections is to verify I have the correct voltage at the source. Use you multimeter set to the correct voltage at the genset output. I suspect you will have two hots, a neutral and ground comming out of the genset. I would check from hot to hot looking for 220 and from hot to neutral looking for 110. I also check hot to ground to make sure things are as the should be. If your hot leg is bad at the genset output, you shoud probably seek professional help.

If all is good comming out of the genset then go to where your first component without power is and verify the voltage there. Check for voltage from hot to neutral and hot to ground. If you get 110 from hot to ground and not at hot to neutral, then you have a open neutral somewhere between. If not 110 then you have a open hot.

Locating an open wire in a harness that runs through enclosed spaces can be difficult. I alway try to locate an component between the source and the place you have no voltage, and test there next. I keep splitting the known good and known bad until I find the problem.

A picture of the shorepower/generator selector switch connections would be great if you are not sure where to check for the correct voltage.

Good luck