Author Topic: Surge Protector Wiring  (Read 178 times)

labusker

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Surge Protector Wiring
« on: September 18, 2019, 11:34:36 AM »
What is the proper way to connect the positive wire from the surge protector to the positive side of the circuit in a MNPV3, MNPV6, or MNEDC125 box. There are no positive bussbars in these to make that connection.
Drew

Vic

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Re: Surge Protector Wiring
« Reply #1 on: September 18, 2019, 12:47:12 PM »
One common method of connecting an SPD to the positive,  or line circuit,  is to add a breaker,   and connect the hot SPD wire to this breaker,  if there is a spare breaker position available.  The SPD wire will be the only connection to the added breaker.

Some of the recent Combiners may have an extra hole in the positive busbar,  for an added machine screw/nut in the buss.   A ring terminal could be crimped onto the SPD's hot wire,  and this terminal connected to the screw that was added.

IMO,    Vic
« Last Edit: September 18, 2019, 01:08:51 PM by Vic »
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

labusker

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Re: Surge Protector Wiring
« Reply #2 on: October 10, 2019, 11:12:28 AM »
I am not getting reply notices in my email. Is this possible?
If the SPD was connected to a breaker 1st, then if that breaker was off somehow, then I guess the SPD could not do its job!
I would rather put the SPD inside near the controller in the MNEDC175. Does it matter what side of the controller it is put, input or output?. If its on the input, then what is the proper way to connect the SPD without a positive busbar?
Drew

ClassicCrazy

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Re: Surge Protector Wiring
« Reply #3 on: October 10, 2019, 11:58:07 AM »
I am not getting reply notices in my email. Is this possible?
If the SPD was connected to a breaker 1st, then if that breaker was off somehow, then I guess the SPD could not do its job!
I would rather put the SPD inside near the controller in the MNEDC175. Does it matter what side of the controller it is put, input or output?. If its on the input, then what is the proper way to connect the SPD without a positive busbar?

Me - I would just put it in the terminal with the larger wire and they will be tightened together and the electrons won't care .

Larry
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

Vic

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Re: Surge Protector Wiring
« Reply #4 on: October 10, 2019, 01:09:01 PM »
Hi lab..,

The SPD  for the PVs needs to be as  close  to the PVs,  as it can  be.  At the PV Combiner is the best place for it.

The standard practice,  is to use a MNEPV breaker  inside the Combiner (or,   for an AC panel,  a breaker is often used,  and is Code IMO).

There should be no reason,   whatsoever,   that an MNEPV breaker would switch itself off.   Even seems unlikely that in the event of a close-by lightning strike,   that this breaker would trip.   The SPDs have an internal fuse,  to protect it from MOVs shorting,  from a large surge event.

Believe that using a screw and crimp terminal for the connection to the bussbar in the Combiner,  should pass inspection.

Most wire connection terminals are not rated for multiple wire/cable connections.  Would probably work  fine in most situations,  but,  believe that this is not Code compliant  --  considered unreliable.

Opinions from someone who is NOT a Code wizard.   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

Vic

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Re: Surge Protector Wiring
« Reply #5 on: October 10, 2019, 05:55:43 PM »
I am not getting reply notices in my email. Is this possible?

Under "Profile"> Account Settings,   do not  see an  option for  e-mail notification  on Replies.

There  may be a  way,   but do not see  it.    FWIW,   Vic
« Last Edit: October 10, 2019, 05:57:53 PM by Vic »
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!