Author Topic: SPD on a Trailer Based Chassis Grounded System  (Read 505 times)


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SPD on a Trailer Based Chassis Grounded System
« on: January 27, 2017, 09:13:37 AM »
Hi all

I curious to know how you would go about installing a SPD on a purely 24V DC chassis grounded electrical system.

The electrical system utilises the chassis as a ground reference. I've got a 24V battery system and trailer mounted PV array with a DC generator on board. No AC, no inverters. I've deployed an earth stake which is also connected to the trailer chassis (I've got some antennas connected to the trailer).

Just interested to know how you would utilise a Midnite Solar SPD in this situation. Would I tie the 0V and Ground wires to the same terminal and trunk this connection to the earth stake?

Thanks for your input!


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Re: SPD on a Trailer Based Chassis Grounded System
« Reply #1 on: January 27, 2017, 03:44:51 PM »
you should check to see if the battery - is connected to the chassis. if so you can tie the - and ground together on the spd  and take it to either the battery or chassis ground otherwise keep them separate going to their appropriate - and ground. if - and chassis ground are tied together you will be able to ground out the positive surge spikes, but not the negative on the spd. the negative spikes should make their way straight to the earth stake you placed and not need to pass through an spd. hope this clarifies it for you.
« Last Edit: January 27, 2017, 03:48:05 PM by niel »


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Re: SPD on a Trailer Based Chassis Grounded System
« Reply #2 on: April 06, 2017, 02:44:18 AM »

I have two 40 foot high cube all metal shipping container workshops which are solar powered. my 24 volt battery banks are bonded to the metal framework and I do have ground rods bonded to the all metal frame on the shipping containers. The arrays are on top of the containers and my spd' are qrounded directly to the ground rods with heavy gauge wire which does not enter the container on the theory that I want a lighting strike to stay outside. Each array has its own MNPV6 combiner with its own MN300DC SPD. Two Classic 150's.   I have multiple communications antennas which have lightening protection as well.

I'm an commercial electrician and have repaired lighting damage and know that there is no way to predict just what lighting will do when it strikes. I also have (2) MN300AC SPD's on my AC system, one on the generator (outside the container) and one shared by the Inverters. ( I use a small inverter for basics and a much larger one power needs).   Haven't needed them but cheap insurance.

#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 2 Suntech 280 24v AGM 105 a.h. Exeltech Inv.
#4 Kid/WBjr 2 Suntech 280 12v AGM 105 a.h.