Grunaire GMU028HXB-4 wiring question???

[danoseven]

Thanks in advance for your help. I recently purchased a grunaire mini split system from acwholesalers, (one outdoor unit and four inside). I'm having a little trouble understanding the wiring on the units. The wiring is 14 gauge (red,blk,wht,grn). The outdoor unit list N(1) 2 3 and then the symbol for ground per each unit and L L2 and ground symbol for the power. There are also an additional 3 or 4 screws off to the left of these inputs marked with ground symbol. For the indoor units would N(1) be white then blk or rd for 2 and 3 and grn for ground? For the power to the unit i was advised to run 8 gauge from a 30amp breaker..blk & rd off of the breaker and wht & grn from the ground bar. The power input on the unit has the L L2 grnd, would the grn wire go to the ground here and the white to one of the other ground screws? Thanks again for the help.

[Brian_UK]

What does it say in the installation manual that came with the equipment?

[danoseven]

The documentation supplied is extremely limited. I tried to copy the link to the owners manual but apparently i have to have at least 15 posts in before i can do that. The model number is GMU028HXB-4 and can be found at grunaire.com under customer support - manuals & literature. Thanks again

[Brian_UK]

OK, had a look at the manual, thanks for the link.

Starting with the interconnecting wires first, I would use the following system.....

N(1) - Black
2 - Red
3 - White
Earth - Green

Power In cable...

Live Side - Red
Neutral - Black
Earth - White and Green, using both cables provides a stronger earth connection.

Now the extra earth screws....

You need to run some green cable, if you have spare, from every earth connection point (where you have already fitted the green wires) back to the bank of earthing screws.

Also make a connection from your incoming earth to the earthing screws.

Hope this makes sense to you and good luck with the installation.

[danoseven]

Thank you very much. I'll let you know how it works out.

[kevperro]

Thank you very much. I'll let you know how it works out.

Also... there is a screen wire on the interconnect cable. It has a small diameter wire that connects to the foil shield. Ground it at the outdoor unit only via one of the earth connections. Just trim it at the indoor connection and leave the shield disconnected on the indoor unit.