Mastervolt Fault?

[Ray]

We bought our Mastervolt 2000 at the IWA rally in 2006, before we even bought our boat! It lived in its box in our bedroom for several months and was finally installed in the boat around the middle of this year as we proceeded with the fit out.

 

Apart from a trip to Braunston with the boat and a few local jollies varying in length between a few hours and a day, our boat has sat on its moorings and I've been working on it about six days out of each seven. My routine is the same. Arrive at the boat, usually between eight and nine in the morning and turn on battery master switch and the Mastervolt (in that order). I usually pack up around 5pm and turn the Mastervolt and battery master switch off (in that order) as I leave the boat. We're connected to a land line, which is plugged in all the time (even when the boat isn't occuppied).

 

On Monday evening I turned the battery master switch off first for some reason and noted that there weren't any lights on the Mastervolt when I went to turn that off. I turned it on again, but there were still no indicator lights. It was getting dark so, apart from a cursory check that we appeared to have power through the MCB's on position, I did nothing.

 

I wasn't at the boat yesterday (and was dreading finding the inverter had packed up).

 

This morning I went through my usual routine. The indicaor lights on the inverter illuminated, indicating that a mains supply was present. The fan on the unit even started going. With a busy programme, I didn't hang about and disappeared into the bowels of the boat, not giving the inverter any more thought.

 

This evening, as I locked up, I noticed that the mains light on the inverter was out before I switched off. In fact, we were cleaning the boat prior to a week long trip and the vac kept cutting out, probably indicating that the Mastervolt hasn't been charging for some while and we've been running the batteries down - we have a bank of 5 * 110ah domestic batteries plus the starter battery.

 

My multimeter has died, I'm not around tomorrow and we're due to set out on our trip early on Friday morning. It looks like we have a problem somewhere. We do have a fuse in the shore line because part of the link is temporarily through a normal extension lead with 13amp sockets. I haven't checked the fuse in the plug, nor have I opened the Mastervolt to see if there's a fuse or breaker in there which has blown/tripped. I'm hopeful that it is a simple as that but has anyone else heard of this kind of problem with a Mastervolt before? I'm guessing that the illumination of the indicator lights when the unit is first switched on is part of the start up routine and that the absence of mains input would show up if I stayed around the unit a bit longer.

 

Luckily, we don't plan to use the mains input side of the Mastervolt while we're away, but I'd like to prepare myself for the worst when we get back.

 

Ray

[Ray]

Fortunately, it was the fuse. We'd recycled a short length of wire that we'd initially used for the original and temporary lights that we fitted when we first got the boat. We put a 5 amp fuse in the plug for safety. When we re-used the plug for the inverter lead we didn't bother to check the fuse and it was that that blew. We replaced it with a 13amp fuse and the Mastervolt was back in action.

[Ray]

It seems daft to start another thread with a similar title even of the fault is different!

 

We've suspected for a while that one of our batteries has been unwell but haven't had a chance to do anything about it until Wednesday evening when we connected the Mastervolt to the shoreline and turned the charger on.

 

It took a couple of attempts to get the Mastervolt charging correctly but we left the boat with the Mastervolt on and the battery isolation switch off.

 

The plan was for our colleague to turn the charger off for us on Thursday evening and disconnect the links between the batteries so that we could give the batteries a drop test and see if we had a sick one on Friday morning.

 

Apparently around 02.00 on Thursday morning either one of our two smoke alarms or our CO alarm went off for no apparent reason - it has happened before and we put it down to condensation when the outside temperature drops.

 

Our friends in the boat behind, having been woken, checked our boat, could find nothing wrong, removed the battery from the detector and also disconnected the mains withour turning the Mastervolt off beforehand.

 

Nothing further was done until this morning when the battery links were temporarily disconnected. A quick voltage check on each revealed a sick battery although not the one we suspected. The voltage of the "good" battteries was around 12.6v, a few tenths of a volt below our starter battery voltage.

 

A couple of hours later we drop tested the batteries and our earlier suspicions were confirmed. One sick battery and the others seemingly working OK.

 

We removed the dud battery and replaced it with a borrowed two year old used standby that easily passed the drop test.

 

Everything was reconnected and checked and the Mastervolt was reconected to the shoreline and the charger turned on. Nothing, not even indicator lights (although, when we then turned the Masterwolt off, we did briefly get a couple of lights momentarily illuminated).

 

The inverter was switched on and fired up but the "Mains Present" light didn't illuminate. The test button on the RCBO on the input to the Mastervolt tripped, suggesting that AC volts were getting that far.

 

At this point I had to depart as I was already running late for an appointment.

 

I've checked the manual on-line tonight and other then a reference to a thermal fuse (which I have yet to attempt to reset) I can find nothing else to help me work out what is wrong.

 

Because the inverter side of the Mastervolt seems to fire up the problem seems to be on the AC input side.

 

Does anyone have any ideas what might be wrong? Is it most likely to be the thermal fuse just needing resetting?

 

The Mastervolt is about 4 years old. We're not liveaboards and the boat has seen little use over the last eleven months due to family illness. That said and with usage a bit greater prior to that, the charger side has seldom been used.