York Single Package Air Conditioner ZR078N20A2AAA50124A

Inspect the unit for visible damage during transit

Note the extent of any damage on the carrier’s freight bill

Request inspection by the carrier’s agent in writing

Ensure installation complies with local, state, and national codes

Verify compliance with building, electrical, and mechanical codes

Check that all filters are in place

Clean the filters if they are dirty

Replace filters if cleaning is not possible

Ensure filters are installed ahead of evaporator coil

Verify that the correct number and size of filters are installed

Close main manual shut-off valve

Open the union fitting upstream of the unit gas valve and downstream from the main manual shut-off valve

Remove screws holding each end of the manifold to the manifold supports

Disconnect wiring to the gas valve

Remove the manifold & gas valve assembly

Review installation for errors, leaks, or undesirable system effects

Is the current blower speed causing any issues?

Enter the existing datum diameter (DD)

Calculate the new datum diameter (DD) using the formula: (Required CFM/Measured CFM)*Existing DD

Has the new datum diameter (DD) been set correctly?

Verify proper compressor rotation

Check blower rotation direction

Is the electrical connection properly phased?

Is the line voltage at the unit point of power connection correctly phased?

Check for signs of misphasing in scroll compressors