950-0289revB - 23 - July 22, 2022
START UP TESTING
Preparation
1. Double check that all wiring has been properly connected.
2. Check that tubing has been properly connected and ensure the suction and liquid side service valves are
fully open.
3. Review remote control functions in the Operators manual.
Note:
A wall control is optional
7DP120X (246-1002). For the details of installation and operation, please refer
to the manual to be placed with the wall control.
Operational Test
Note:
For model: MZ18H424ZMO, MZ27H424ZMO, MZ36H424ZMO,
MZ48H424ZMO
The cooling test may be performed if the outdoor temperature is between -13 ºF to 122 ºF.
The heating test may be performed if the outdoor temperature is between -13 ºF to 86 ºF.
For model: HMZ18H424ZMO, HMZ28H424ZMO, HMZ36H424ZMO,
HMZ48H424ZMO
The cooling test may be performed if the outdoor temperature is between -22 ºF to 122 ºF.
The heating test may be performed if the outdoor temperature is between -22 ºF to 86 ºF.
1) With the unit t
urned on, press the mode button and select “COOL” mode for all indoor units (see
Note
above). Allow 3 minutes for compressor delay timer to expire.
2) Press t
he “
∨
” button until it reads 60 ºF on all indoor units.
3) Operate indoor units for no less than 15 minutes in the cooling mode.
4)
Press the “FAN” button to select high fan speed on all units.
5) After operating for several minutes, check for cool air flow. Outlet temperature should be 20 to 24 ºF lower
than ambient temperature. (If outlet temperature is out of range contact technical support).
6) If cooling mode is operating properly, check for proper heat operation.
7)
Press the mode button to select “HEAT” (see
Note
above).
8)
Press the “
∧
” button until it reads 86 ºF.
9) Allow approximately 5 minutes for compressor delay timer to expire before unit will operate.
10) The indoor fan will turn on and heat should be present.
11) If unit(s) does not perform as described, see the troubleshooting section.
12) All functions should be tested for operation, see Operation manual. Review remote control functions with
owner.
13) Emergency operation button
– test to confirm proper operation (see Operation Manual).
Notes:
1. Indoor fan will not turn off in the cooling mode.
2. Indoor fan will turn off in heating mode shortly after the set point has been satisfied.
3. Unit may require several minutes to confirm the condition of temperature set point and system functions.
