Installation Guide
Page 44mrcool.com
Refrigerant Piping Connection
AFTER PERFORMING GAS LEAK CHECKS
After confirming that all of the refrigerant pipe 
connections points DO NOT leak, replace the 
valve cover on the outside unit and wrap and 
insulate the piping connections of the 
indoor unit.
8
BEFORE TEST RUN
9
Using a soft brush or spray bottle, apply a soapy 
water solution to all of the pipe connection points of 
the indoor and outdoor units, watching to see if any 
bubbles form. The presence of bubbles indicates 
there is a leak.
There are two different methods to check for 
gaseous leaks. Use Fig. 9.1 below as a guide for 
the critical points to check for leaks.
Soap and Water Method
Leak Detector Method
If using a leak detector, refer to the device’s 
operation/instruction manual for proper usage 
instructions.
Gas Leak Checks
Electrical and Gas Leak Checks 
IF ELECTRICAL LEAKAGE IS DETECTED
If electrical leakage is detected, turn off the 
unit immediately and call a licensed 
electrician to find and resolve the cause of 
the leakage.
After installation is complete, confirm that all 
electrical wiring has been installed in accordance 
with local and national regulations, and according 
to the installation manual.
Check Insulated Resistance
The insulated resistance must be more than 2MΩ.
Check Grounding Work
Measure grounding resistance by visual detection 
and with a grounding resistance tester. Grounding 
resistance must be less than 0.1Ω. 
NOTE: This may not be required for some 
locations in North America. 
Check for Electrical Leakage
During the Test Run, use an electroprobe and 
multimeter to perform a comprehensive electrical 
leakage test.
NOTE: This may not be required for some 
locations in North America.
Electrical Safety Checks
DURING TEST RUN
WARNING – RISK OF 
ELECTRICAL SHOCK 
ALL WIRING MUST BE INSTALLED BY A 
LICENSED ELECTRICIAN AND COMPLY WITH 
LOCAL, STATE, AND NATIONAL ELECTRICAL 
CODES.
Fig. 9.1
Indoor unit 
check points
Outdoor unit 
check points
NOTE: The illustration above is for demonstration 
purposes only. The actual order of the A, B, C, D, 
and E valves on your system may be slightly 
different from what is shown, however, the 
general shape will remain the same.










