MNPV10 and 12 Manual

MNPV10, MNPV12 Combiner Instructions (continued)
8 | P a g e 10- 2 5 9 - 1 R E V : D
The regular MNPV12 comes with a 1/8” thick reversible copper busbar. This busbar may be used with fuse
holders above or with 150VDC breakers shown below. The busbars are rated for up to 200 amps.
MNPV12 with breakers combined MNPV12 breaker wiring diagram-combined busbars
Some PV Panels now require a 20 amp series fuse (breaker). The MNPV12 can support ten high voltage 20
amp fuses or breakers. This combiner can accommodate all twelve positions when using 15 amp or less
breakers.
When selecting breakers for use with the MidNite combiners, first check with the PV manufacturer to
determine the proper “series fuse”. The term fuse is used even though you are probably using breakers. This
is a carry over from UL terminology.
MidNite Solar offers PV combiner breakers rated up to 150VDC and 300VDC. The 150V version come in
these current ratings. 1,2,3,4,5,6,7,8,9,10,12, 15, 20, 30, 40, 50 and 63. The 300V version is available in 10,
15, 20, 30 and 50 amps. Other sizes are available on special order.
Part numbers for breakers are as follows:
MNEPV10, MNEPV15, MNEPV20 etc for 150 volt breakers. Part numbers for 300 volt breakers are
MNEPV10-250, MNEPV15-250 etc.
The MidNite MNPV12 can utilize touch safe fuse holders and fuses rated for up to 1000 volts DC for high
voltage strings. The MNPV12 comes with a special busbar that has reversible legs to accommodate ten of
these USM1 type fuse holders made by Ferraz Shawmut (Mersen). Use MidNite Solar 1000 Volt fuses. Fuses
are available from 1 to 30 amps.
Tighten fuse/circuit breaker connections to the torque indicated in the table below.
Important! Re-torque after one hour. Do not skip this step. You may be surprised by how much the
connections may loosen after the initial tightening.
Torque –Fuseholder / Circuit Breaker
QY Circuit breakers 20 in-lbs (2.3Nm)
USM1 Fuseholders 15 in-lbs (1.7Nm)