Mitsubishi Electric PAA-A18AA1 Service Manual page 5

WARNING
Electrical risks
• When sizing wire and completing electrical connections during installation, please follow
local codes and standards.
– Inadequate connections and fastening may generate heat and cause a fire.
• Have all electric work performed by a properly qualified electrician in the state where the
electric work is being performed, according to the "National Electrical Code" and local
electrical codes, "Interior Wire Regulations" and the instructions provided in this service
manual, and always use a dedicated circuit.
– If the power source capacity is inadequate or electric work is performed improperly,
electric shock or fire may result.
• Keep the electric parts away from water.
– It might result in electric shock, fire, or smoke.
• Do not reconstruct or change the settings of the protection devices.
– If the pressure switch, thermal switch, float switch or other protection devices are
shorted and operated forcibly, or parts other than those specified by Mitsubishi Electric
are used, fire or explosion may result.
• If the supply cord is damaged, it must be replaced by the manufacturer service
personnel or licensed person.
• Be sure to ground the outdoor unit in accordance with local code. Do not connect the
earth cable to any gas pipe, water pipe, lightning rod, or telephone earth cable.
WARNING
Refrigerant leak risks
• If refrigerant gas leaks during service work, ventilate the room and do not use the
furnace until a technician considers that it is safe to use the furnace.
– If the refrigerant gas comes into contact with a flame, poisonous gases will be
released. When the odor is detected, contact a dealer, contractor or technician
regarding the appropriate measures to prevent the safety limit from being exceeded.
• After completing service work, make sure that refrigerant gas is not leaking.
– If the refrigerant gas leaks and is exposed to a fan heater, stove, oven, or another
heat source, it may generate noxious gases.
• Do not use refrigerant other than R410A.
– Doing so may cause the unit or pipes to burst, or result in an explosion during use,
repair, or at the time of disposal of the unit.
– Doing so may also be in violation of applicable laws.
– The manufacturer, Mitsubishi Electric Corporation, its affiliates and suppliers, cannot
be held responsible for malfunctions or accidents resulting from the wrong type of
refrigerant used.
• When the outdoor unit service valve is left closed after installation/service, or when
the outdoor unit service valve is closed due to operation stop, the volume of the
liquid refrigerant in the A-Coil and refrigerant piping will expand due to the the heating
operation in the gas furnace. This may cause the A-Coil or refrigerant piping to rupture.
Specifications are subject to change without notice.
PAA-A18, 24, 30, 36, 42AA1/BA1/CA1
5 © 2022 Mitsubishi Electric US, Inc.