Inverter can the connection be changed?

Submitted: Wednesday, Aug 14, 2019 at 10:03
ThreadID: 138930 Views:960 Replies:2 FollowUps:5
I recently bought a 400w pure sinewave inverter to use with big family's tech stuff, (not for heating devices, cooling devices or TVs) in both tugs and campers where there is access to either cigarette and/or merit plugs. Problem, on opening it at home I found this thing comes with alligator clips so I would like cut them off and attach a combination cigarette/merit plug however this is starting to ring alarm bells in my naive electrical mind. What do you reckon?

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Reply By: MickeyJ - Wednesday, Aug 14, 2019 at 11:03

Wednesday, Aug 14, 2019 at 11:03
400 W @ 240V is 1.6 Amps which is 35 Amps at 12V . You cannot run 35Amps through a merit or cig socket. Maybe hardwired to Auxiliary battery with big cable or a 40Amp Andersen plug.


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Follow Up By: Nomadic Navara - Friday, Aug 16, 2019 at 08:42

Friday, Aug 16, 2019 at 08:42
See if you can swap the inverter for a smaller one. Something around 100 - 150 W is plenty. You then could run it from a merit socket.
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Follow Up By: tim_c - Friday, Aug 16, 2019 at 11:26

Friday, Aug 16, 2019 at 11:26
No need to swap the inverter you already have - a 400W inverter will only draw 35A when operating at full load. If only running at 100W, it will draw a similar current to a 100W inverter running at 100W - the load is more relevant than the maximum capacity of the inverter.

The first inverter I purchased (300W) had two sets of connectors - one for low power use (with a cig. plug), and another for higher power use (with alligator clips). Each was fused appropriately for the expected load.

If you're only running low power appliances, you'd be fine to run it through a merit plug, though given that the inverter has capacity for much more than a merit plug could handle, I'd put a 10-15A fuse in the wire so that if someone does try to run a bigger load from the inverter, the fuse will melt rather than the internals of the merit plug/socket.
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Reply By: RMD - Wednesday, Aug 14, 2019 at 11:32

Wednesday, Aug 14, 2019 at 11:32
AS MickeyJ says, you can't run that size inverter from such a small capacity 12v outlet.
Best option is to have a heavy 12v 30A fused supply wired to an Anderson plug from whichever battery you prefer. The Inverter can also have a heavy 12v lead and Anderson plug to allow easy removal. That way it will cater for most of your 240 output needs and with the 30 amp fuse in it's direct supply, it will blow before you get near 400w 240ac output. ie, load limit. Remember it outputs 240ac and is lethal if appropriate safety is not observed. Dry areas only.
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Follow Up By: MickeyJ - Wednesday, Aug 14, 2019 at 11:41

Wednesday, Aug 14, 2019 at 11:41
For fusing I would check what the inverter comes with. Many of the quality inverters will do 2* peak for motor startup etc so may draw 50A for a short period if you wanted to run a small power tool. Check what the manufacturer recommends.

Enerdrive recommends for their 400 W inverter an 80AMP fuse.

Also pushing the limits of a 40 AMP Andersen plug.
FollowupID: 901224

Follow Up By: Keir & Marg - Wednesday, Aug 14, 2019 at 15:43

Wednesday, Aug 14, 2019 at 15:43
From an earlier thread on here:

The standard grey SB50 Anderson is rated around 120amps.Feb 14, 2017
Amps through the Anderson Plug - ExplorOz
FollowupID: 901226

Follow Up By: Crusader - Wednesday, Aug 14, 2019 at 16:16

Wednesday, Aug 14, 2019 at 16:16
I assume the OP is using a SBS 50 Anderson plug:

From Anderson Power Products website - see page 53: SBS 50 product specs

According to this document the connection are rated at 50 Amps and sorry.... but I cant see where it indicates 120 Amps but Ill happily be proven wrong :) I also cant find any reference to "Continuous uninterrupted rating is much higher".

It would be good to find that source of information for future reference.

FollowupID: 901228

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