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Old 12-23-2008
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mbrund mbrund is offline
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Join Date: Dec 2007
Location: Georgetown
Posts: 112

Originally Posted by AC7880 View Post
I have a 94 BB BMC 37' with a original equipment Heart EMS 2800 (HD 2800) modified sine wave inverter with 100 amp charging capability (2 stage).

We will begin fulltiming in 2009. I am considering replacing the old Inverter with a pure sine wave 2800 or 3000 model from Magnum or Xantrex.


94 BB BMC 37'
I replaced my old 2000 watt Heart unit with a Xantrex RS3000, it was a chore to say the least on a Wanderlodge. The Wanderlodge (not sure about the BMC) has a strange setup for the inverter. The Heart inverter has a built in circuit breaker in the inverter, the RS models DO NOT, and thus require that you plumb in a new circuit breaker as Bluebird puts the invertered circuits in after the circuit breaker panel through a set of high voltage relays. There fore those circuits are not protected for over amperage, and if you put in an inverter in that can supply more than 15 AMPS AC you could burn down the coach with out adding proper protection.

These relays are held engaged when you are on shore power, but when shore power fails, the relays disengage and allow the inverter supplied AC to flow to those circuits. Can't remember, but it is either 4 or 6 of the circuits in the coach are on these special relays, all the rest of the circuits are not (such as Air Cond, etc.). So check out how the BMC is wired, and if similar to the Wanderlodge, be careful and make sure you protect the circuits such that you can't overload them.

I replumbed my whole AC panel and circuits, and put a new 50AMP breaker in ahead of the new RS3000 since it has a transfer switch built in. I then plumbed the output circuit from the inverter back to the original coach main breaker. So everything in the coach is on the inverter. I would suggest you not do this unless you are willing to put larger DC cables in to support the full load of the inverter and also put a generator auto-start panel in to kick the generator on when the AC fails and the draw on the inverter is large enough that the generator is needed. Otherwise you may pop the fuse on the DC input to the inverter (I have done this once, quite by accident flipped on the air compressor forgetting I was on inverter, it was a 200 AMP DC fuse, should have been a 300 AMP to support 3000 watts AC. I plan to replace the fuse with a pair of paralleled 150 AMP DC circuit breakers so I don't get stranded without a fuse).

Since you have a 2800 watt unit, sounds like the BMC is plumbed different. Make sure to determine how the inverter is plumbed into the AC circuits (before or after the main AC breaker panel). If after, you need to protect the output of the inverter with an AC circuit breaker. Also keep in mind in such a case, that this circuit breaker should not be larger than the smallest circuit on the inverted output can sustain without overloading the AC wire gauge (so if it is 14/2 romex, 15AMPS, etc.).

One last note: The RS models have the ability to dial back the AC input power so the charger does not consume lots of AC AMPS. So if you are on a 30 AMP circuit, you can dial it back to 30 AMPS and the charger will only use what power is left on the AC input after all the other coach circuits. So that way if you want keep the battery charger from eating lots of AC power at a friends place, you can set it from the control panel.
Michael Brundridge
1992 Bluebird WB40 (formerly owned)
2002 Prevost H3-45 Vantare (formerly owned)
Fredericksburg, TX

Last edited by mbrund; 12-23-2008 at 03:24 AM.
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