Electrical Power Shedding

[bobbyks]

I own a 2008 Mandalay 43-C with a Magnun 2012 charger/inverter, I replaced the 4- 6 volt batteries in November 2012 and since having problems with volt drop and shedding in the am when we start turning on power( lights, coffee pot, micro, heat pump and others. Start out with 12.3 V and drops to around 11 or below, I reduce load and select items in order not to drain batteries, at night when load is at min the system will come back to 12.0 to 12.5, after 24 hours with min draw the system levels out at 13.5 to 13.8 on float charge.I maintain sufficient water levels in the batteries.

The system is set as follows:

Search watts 30 W, low battery cut out 120 VDC,Batt Amp HRS 200, Batt Type Flooded, Rate charge 10%, VAC Dropout 60 VAC.

The settings I assume were set be Dealer when they installed new batteries.

Any feed back or suggestions will be great.

[dickandlois]

Edited 1-6-13. you mention problems with volt drop and shedding. There is a current loop inside the AC Breaker box that senses current flow in the primary AC feed. this loop sensor tells the power sharing circuits to shed loads down to an acceptable level. The Loop is not in the inverter section of the circuit.

There are 2 circuits that are being powered from the Inverters in most cases. One 20 amp for the Microwave and one 15 amp for general appliances.

I do not have the wiring information for your model coach, so I'm limited in information.The items listed are rather large loads for the inverter.I do not think that all the items you listed would be powered from an inverter system.

We run the Generator in the AM for a short time when not on shore power, until we are done with the Microwave,toaster and coffee to start the morning. Our coach does not have heat pumps, and in your case this is also a hefty load until the set temperature is reached, even then asking the inverter to supply power to the heat pump places a continual load on the batteries. One needs to remember that there is a constant load to supply 12 volts to a number of items from the batteries. Even with supplemental solar panels there output is limited due to the low sun angle in the AM limiting there output. A small supplemental wind turbine has limits.

Increasing the number of Coach batteries would help,but not completely solve a high load request. You would need to decide if the added weight, space requirements and cost are a good choice or just use up some fuel for a short time is more cost effective.

Rich.

[desertdeals69]

The heat pump draws as much current as the ac. It should never be hooked up to the inverter. The microwave on mine draws about 190 amps from the batteries.

[bobbyks]

****, do the settings look norm on the chsrger/inv?

[desertdeals69]

It looks like the settings are off. Check the owners manual. The battery amps should be somewhere around 420. When the batteries are fully charged the voltage is 12.6 with no load.

[dickandlois]

Bob,

In regards to your question, ome of the information is OK just miss stated from my point, not a critical issue.

Regarding the Flooded cells OK, Rated Amp Hrs. what battery manufacture and part number? The charge numbers look to be on the low side,but a lower rate will reduce the water lose and the system could be putting out more then is coming in under different loads during the day. 10% ???

The VAC dropout is lower then normal, but again the type batteries come into play. The batteries do reach the float setting over night. So it looks like its operating as programed.

Rich.

[dickandlois]

Bob,

I just realized that your coach is a newer model and maybe equipped with the Intellitec EMS series power management system. This type of set up could be programed to shed different items, powered by the Generator, shore power or the inverter in some cases.

This link will lead to a manual for the 800 series 50 amp. There is a switch to select for 30 and 20 amp applications. The other unit is refereed to as a load meter EMS 750. both are very similar.

EMS circuits 1,2,3,and 4 are rated at 15 amps or 1 horsepower (745 Watts) EMS circuits 5 and 6 are for the AC units. Circuits 1 and 3 feeds are from one main 50 amp breaker and Circuits 2 and 4 feeds are form the other 50 amp breaker.

Relays in the EMS control box open relays, these open the supply of power to the program set up in the controller to shed appliances as programed into the controller.

This is not part of the inverter it's self, but is directly responsible for controlling load current information and drops items if the current exceeds supply.

http://www.rvcruzer.com/docs/EMS800_SvcManual.pdf

Good luck,

Rich.