Author Topic: Where to install SPD's and how many required for proper protection?  (Read 364 times)


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Hello  there,

I would like to know where to install the SPD,s, what type of SPD to use for each location and of course the best way to wire them in?
I've already watched all the videos on the Midnite website and I  will read through the posts re: SPD's on the Forum, but also thought I'd better post my questions directly, as it pertains to my situation in particular, for greater clarity.
As of now I have one MNSPD-115, one MNSPD-300-AC and two MNSPD-300-DC's in boxes ready to be installed.

The equip I have set up now that my require SPD's installed:

MNPV6-Disco (for the solar array)

MNDC250-L (battery bank disconnect)

Schneider XW+ 6848

Two - Schneider MPPT 60/150's

A 60 amp load center that only runs a few 120V outlets in the power room

I also have Schneider Battery Monitor, SCP, Combox and AGS.

Thank you for any support and direction that may be avail through this forum.
« Last Edit: October 09, 2018, 05:23:34 PM by ligwyd »


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Re: Where to install SPD's and how many required for proper protection?
« Reply #1 on: October 09, 2018, 08:02:02 PM »
Have you looked at the E-Box spes for their wiring diagrams, most now have the SPD's included.  Link can be found on the main MN site page,  top of page under 'Products' ...
KID FW1811 560W >C&D 24V 900Ah AGM
CL150 29032 FW V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub
Cotek ST1500 Inv  want a 24V  ROSIE Inverter
OmniCharge3024  Eu1/2/3000iGens
West Chilcotin 1680+W to come


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Re: Where to install SPD's and how many required for proper protection?
« Reply #2 on: October 10, 2018, 12:58:08 AM »
Thanks. Reading up right now.

Question: I am using two Schneider Mppt 60 150's. Since I have split the positive bus bar in the combiner and the negative has separate bus bars as well do I need two 300VDC SPD's on my combiner box? I would think so but god to ask?

Also, what is the best method of terminating the 12 awg SPD wires to the positive bus bars in the combiner. If that is a stupid question I'll just do it sensibly. Be nice if there was a place for it to terminate. Maybe drill a small hole if the bus bar and use a small stainless machine screw with lock washer and a crimp on ring connector?

Can the SPD's be mounted on the top of the combiner if it is outside? Putting holes in the top of the combiner when there are holes provided in the sides might be silly but I think it might look better, less chance of someone hanging off a side mounted unit and the rubber washer would seal the combiner against water leakage? Thoughts?

Re: the AC side, is it simply a matter of talking the shortest path to ground, when determining whether to run the green SPD wire to Neutral bus bar or Ground bus bar?

« Last Edit: October 10, 2018, 05:33:48 PM by ligwyd »