Trying to understand MultiPlus-II Power Assist

DIY
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1

I am at my son’s house mooch docking with my RV in the USA. I have a MultiPlus-II 12/3000 120-50 2x120V. I am connected to my son’s garage using a standard 15a household outlet. I have an air conditioner that uses around 1400 watts to run. It has a soft start attached to it. The Ac Input 1 Current Limit is set to 15a on the MultiPlus-II.

When I turn on my on the air conditioner and the condenser kicks in, my system shows around 1550 watts coming in from the household outlet and my battery is being charged. As the battery becomes fully charged and gets to 0a being charged, Power Assist kicks in. It immediately reduces the 1550 incoming watts to around 1120 watts and assists with 430 watts from the battery. Why does Power Assist reduce my 1550 incoming watts?

2

Most likely what is happening is that when you first turn on the air con the watts are just under the incoming ac current limit. As the air con continues to run the compressor warms up. As the compressor warms up the current also increases. This most likely pushes the current nearer the ac input current limit. The inverter has a minimum power assist current, so if the current being drawn by the air con is just a few watts over the ac current limit the power assist kicks in reducing the ac input current by a minimum of the power assist minimum current. This often results in leaving some of the ac input current limit on the table.

3

Thank you for the explanation.