These powder-coated aluminum, rainproof array combiners will accept DIN mount 150 V circuit breakers, MidNite 300 VDC breakers, or 600 VDC fuse holders for grid-tie arrays. A plastic cover provides a dead front for safety and can be knocked out for either breakers or fuse holders. Both a negative busbar and ground bar are included. The aluminum NEMA 3R enclosures are approved to be mounted at angles from 90 to 14 degrees (14 degrees = 3/12 slope). Listed to UL 1741 for the U.S. and Canada. Breakers and fuse holders are not included.
The MidNite Disco line of PV combiners with disconnects incorporates NEC 2011 requirements. The disconnect handle is bright red for visibility and can be locked in the off position. Several models can be configured for bi-polar or ungrounded inverters where both the positive and negative legs of the array need circuit protection (maximum output current is split also). Models are available for 150 VDC, 300 VDC, 600 VDC, or 1000 VDC arrays. All of the combiners are made from powder coated aluminum for corrosion and sunlight resistance for long life in harsh conditions. A clear see-through dead front is supplied with all disco combiners. Models are available with either NEMA 3R or NEMA 4X ratings. Many of these come with a shunt trip disconnect that enables the MNDiscoPSB to trip the disconnect remotely. An MNSPD-600 is included standard with many of these combiners. See the table below for options are that available or included.
The firefighter approved "Birdhouse" remote actuator should be installed in a visible, easily accessible location so that the array combiners can safely be disconnected from the ground when necessary. The hard wired connection to the disconnect combiners provides positive feedback that the disconnect on the roof has actually been thrown. One Birdhouse can be used to disconnect multiple combiners. The Birdhouse has a speaker and will announce when it is safe to climb onto the roof, and during the day it will inform that there is still voltage present up to the combiner. At night, it will announce that there is no PV voltage present. The Birdhouse is powered by multiple redundant sources. The combiner can be powered using the array using the MNDiscoPSB power supply (standard on the Arc-fault combiners) that will also power the Birdhouse. The Birdhouse also comes with an indoor 120 VAC power supply that can be used as a DC supply, and has an internal backup battery. The power draw of the Birdhouse is only 1 W. Use 600 V CAT5 USE-2 compliant wire to connect the Birdhouse and combiners.
The Arc Fault Disconnecting Combiners feature series or optional parallel arc fault protection, and come standard with string monitoring. These can be monitored via Ethernet or RS485.
When a simple disconnect is needed, the MNDC switch can be used by itself without a combiner and can also be remotely triggered by the Birdhouse.