|
|
Post by lollygagger on Oct 29, 2016 11:55:12 GMT
I have 3 possible AC sources in my boat, land line, inverter and a diesel generator, pretty much everything is Mastervolt and quite elderly.
In the distribution board there is a mastervolt 2-way switch and a Hager135 2 way switch.
One of them buzzes continuously on land line hook up. It's hard to tell, but I think it's the older mastervolt one. Reading the manual, one input is for inverter and the other for generator or shore power. The manual states that when on invertor, it's in neutral state and consumes no energy. That makes sense but I'm going to be hooked up, switch energised and buzzing away until spring.
I haven't chased the wires yet, but I'm guessing the Hager 135 possibly replaced manual switch somewhere. I'm wondering if I could swap the two auto switches round and see if the Hager buzzes more quietly, or maybe not at all?
|
|
|
|
Post by Graham on Oct 29, 2016 12:01:44 GMT
I have 3 possible AC sources in my boat, land line, inverter and a diesel generator, pretty much everything is Mastervolt and quite elderly. In the distribution board there is a mastervolt 2-way switch and a Hager135 2 way switch. One of them buzzes continuously on land line hook up. It's hard to tell, but I think it's the older mastervolt one. Reading the manual, one input is for inverter and the other for generator or shore power. The manual states that when on invertor, it's in neutral state and consumes no energy. That makes sense but I'm going to be hooked up, switch energised and buzzing away until spring. I haven't chased the wires yet, but I'm guessing the Hager 135 possibly replaced manual switch somewhere. I'm wondering if I could swap the two auto switches round and see if the Hager buzzes more quietly, or maybe not at all? Have you checked for loose securing screws. Loose cover etc Please make sure that there is no AC connected when you check |
|
|
|
Post by lollygagger on Oct 29, 2016 12:02:06 GMT
Or not swap, the mastervolt one has an adjustable delay to allow the generator to settle down.
So question is how to stop the buzzing and the answer will probably be to replace it.
On the other hand, if ideally it should be switching between generator and invertor, why is it buzzing on shore power?
|
|
|
|
Post by lollygagger on Oct 29, 2016 12:04:45 GMT
I have 3 possible AC sources in my boat, land line, inverter and a diesel generator, pretty much everything is Mastervolt and quite elderly. In the distribution board there is a mastervolt 2-way switch and a Hager135 2 way switch. One of them buzzes continuously on land line hook up. It's hard to tell, but I think it's the older mastervolt one. Reading the manual, one input is for inverter and the other for generator or shore power. The manual states that when on invertor, it's in neutral state and consumes no energy. That makes sense but I'm going to be hooked up, switch energised and buzzing away until spring. I haven't chased the wires yet, but I'm guessing the Hager 135 possibly replaced manual switch somewhere. I'm wondering if I could swap the two auto switches round and see if the Hager buzzes more quietly, or maybe not at all? Have you checked for loose securing screws. Loose cover etc Please make sure that there is no AC connected when you check The buzz is like a transformer rather than a vibration, if you see what I mean. I'll do as you suggest, thanks. |
|
|
|
Post by tonyqj on Oct 29, 2016 12:10:25 GMT
Or not swap, the mastervolt one has an adjustable delay to allow the generator to settle down. So question is how to stop the buzzing and the answer will probably be to replace it. On the other hand, if ideally it should be switching between generator and invertor, why is it buzzing on shore power? Probably the varnish on the relay coil windings has dried out somewhat, allowing it to buzz gently. Obviously check for anything loose but my bet is that you'll have to put up with it or replace it. It's possible that you could just replace the relay if you know what you're doing. |
|
|
|
Post by tonyqj on Oct 29, 2016 12:12:50 GMT
Basically when on shore power the contactor (relay) energises to switch the power across to that source. So whenever shore power is available the contactor is powered. And it buzzes quietly - not unusual, just irritating.
|
|
|
|
Post by JohnV on Oct 29, 2016 12:20:11 GMT
I will probably get castigated by Tony again but ........ I am a great believer in the adage "when in trouble or in doubt ... give the thing a damn good clout"  I would suggest a clout would be a trifle excessive but you might try a sharp rap with a knuckle. Often with elderly contactors they will wear slightly allowing the keep to come down on the solenoid head askew, sometimes a gentle tap will re-align it and stop or alter the hum. If however it is a transformer core plate you are probably going to have to live with it or change it |
|
|
|
Post by Graham on Oct 29, 2016 12:27:49 GMT
Or not swap, the mastervolt one has an adjustable delay to allow the generator to settle down. So question is how to stop the buzzing and the answer will probably be to replace it. On the other hand, if ideally it should be switching between generator and invertor, why is it buzzing on shore power? Probably the varnish on the relay coil windings has dried out somewhat, allowing it to buzz gently. Obviously check for anything loose but my bet is that you'll have to put up with it or replace it. It's possible that you could just replace the relay if you know what you're doing. Yep that is what I expected. I would tight up every screw/bolt. Particularly if there are some holding the laminations together. |
|
|
|
Post by lollygagger on Oct 29, 2016 12:46:15 GMT
A bit more info gained while tightening screws.
It's been wired with generator and shoreline into the MV switch, then the output of that and invertor are switched with the Hager. The in screws on the Hager were all loose, a couple of turns each. Tightened, plugged back in and still buzzing away.
It's louder than it ought to be IMO, it doesn't annoy that much but if I could stop it I would.
As I've found the generator should be on the timed input, input 1, and instead of invertor the shore line is on input 2, it shouldn't buzz as the relay shouldn't be energised. Maybe it's the Hager.
I need to do more investigating.
|
|
|
|
Post by tonyqj on Oct 29, 2016 12:46:53 GMT
I will probably get castigated by Tony again but ........ I am a great believer in the adage "when in trouble or in doubt ... give the thing a damn good clout" I would suggest a clout would be a trifle excessive but you might try a sharp rap with a knuckle. Often with elderly contactors they will wear slightly allowing the keep to come down on the solenoid head askew, sometimes a gentle tap will re-align it and stop or alter the hum. If however it is a transformer core plate you are probably going to have to live with it or change it Actually a gentle tap could indeed work. If it does then it's probably on it's way out. |
|
|
|
Post by Graham on Oct 29, 2016 12:51:17 GMT
A bit more info gained while tightening screws. It's been wired with generator and shoreline into the MV switch, then the output of that and invertor are switched with the Hager. The in screws on the Hager were all loose, a couple of turns each. Tightened, plugged back in and still buzzing away. It's louder than it ought to be IMO, it doesn't annoy that much but if I could stop it I would. As I've found the generator should be on the timed input, input 1, and instead of invertor the shore line is on input 2, it shouldn't buzz as the relay shouldn't be energised. Maybe it's the Hager. I need to do more investigating. My mind is saying it has been doing it awhile and someone loosened the screws to reduce the noise. Have you got an insulated rod say about 60cm long and between a 1/2 cm and a cm diameter that you could use as a stethoscope? |
|
|
|
Post by lollygagger on Oct 29, 2016 12:53:48 GMT
And more investigation (switching the Hager off!) it's the Hager and I can almost stop the buzzing by pressing hard on it, and the noise is indeed amplified by the consumer unit box.
Thanks for the advice all.
|
|
|
|
Post by lollygagger on Oct 29, 2016 12:56:15 GMT
A bit more info gained while tightening screws. It's been wired with generator and shoreline into the MV switch, then the output of that and invertor are switched with the Hager. The in screws on the Hager were all loose, a couple of turns each. Tightened, plugged back in and still buzzing away. It's louder than it ought to be IMO, it doesn't annoy that much but if I could stop it I would. As I've found the generator should be on the timed input, input 1, and instead of invertor the shore line is on input 2, it shouldn't buzz as the relay shouldn't be energised. Maybe it's the Hager. I need to do more investigating. My mind is saying it has been doing it awhile and someone loosened the screws to reduce the noise. Have you got an insulated rod say about 60cm long and between a 1/2 cm and a cm diameter that you could use as a stethoscope? Indeed I have and have just done that. Inconclusive so I switched the second one in the chain ( the Hager) off. |
|
|
|
Post by lollygagger on Oct 29, 2016 13:03:14 GMT
I will probably get castigated by Tony again but ........ I am a great believer in the adage "when in trouble or in doubt ... give the thing a damn good clout" I would suggest a clout would be a trifle excessive but you might try a sharp rap with a knuckle. Often with elderly contactors they will wear slightly allowing the keep to come down on the solenoid head askew, sometimes a gentle tap will re-align it and stop or alter the hum. If however it is a transformer core plate you are probably going to have to live with it or change it Actually a gentle tap could indeed work. If it does then it's probably on it's way out. I've given it a tap, rude not to! It got louder so I tapped it again and it quietened down. All in all with tightening screws, tapping with a stick and general buggering about prodding wires trying to follow them it's now much quieter, I can't hear it with the door shut at all. Result! |
|
|
|
Post by Graham on Oct 29, 2016 13:12:30 GMT
Hurrah a result for hammer and screwdriver  |
|
