MNPV10 and 12 Manual

MNPV10, MNPV12 Combiner Instructions (continued)
3 | P a g e 10- 2 5 9 - 1 R E V : D
Configurations:
The MNPV12 combiners are listed for outdoor use. These PV combiners are designed for combing PV strings up
to 150 & 300VDC using MNEPVXX circuit breakers, and up to 1000VDC using MNTS touch safe fuse holders.
The MNPV12 comes with a 200 amp plus busbar that works with
up to ten fuse holders or twelve 150VDC circuit breakers.
Two busbars can be joined together, or separated to create two
systems up to 5 strings of fuse holders or 6 strings of breakers
each.
The pictures above to the right show breakers on the top row and fuse holders on the bottom row.
Transformeless systems of up to five strings are supported by the MNPV12 by separating the copper busbars.
One set of fuses is used for the negative string inputs and on set is used for the positive string inputs.
Note:
The NEC requires that the ungrounded conductor(s) in from the solar panels must be overcurrent protected.
Transformerless systems do not ground either the positive or the negative. That is why protection is required
for both sides of the input.
The MNPV12-250 comes with 168 amp busbars that
work with up to six of the MidNite 300VDC breakers.
The MNPV12-250 busbars may be joined to
accommodate 6 strings or separated for two
independent sets of three strings.
Note: The amperage rating of the plus busbars is noted above to help insure that the maximum current rating is
not exceeded in any field configuration.
The MNPV series of combiners may be used as a DC load center as well as a PV combiner.
Note: Touch safe fuse holders should never be opened under load! This is not one of those warnings to gloss
over! If opened under load, you WILL have a fire and it will not stop until the wires burn in half. There is a good
reason we make the enclosures out of metal.
Above: An example of why these
instructions should be followed.
Torque – Terminal Bus Bar
Tighten Bus Bar connections as follows:
10AWG 20 in-lbs (2.3Nm)
8AWG 25 in-lbs (2.8Nm)
6AWG 35 in-lbs (4.0Nm)
4AWG 45 in-lbs (5.1Nm)
2AWG – 1/0 50 in-lbs (5.6Nm)
This symbol indicates a
ground connection.