Safety Considerations - Carrier 50GCQ Series Service And Maintenance Instructions

Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Ventilation (Continuous Fan) . . . . . . . . . . . . . . . . . . 55
FASTENER TORQUE VALUES . . . . . . . . . . . . . . . . . 55
START-UP, RTU OPEN CONTROLS . . . . . . . . . . . . . 55
START-UP, SYSTEMVU CONTROLS . . . . . . . . . . . . 55
General Fan Performance Notes . . . . . . . . . . . . . . . 59
APPENDIX A — MODEL NUMBER 
NOMENCLATURE. . . . . . . . . . . . . . . . . . . . . . . . . . 56
APPENDIX B — PHYSICAL DATA . . . . . . . . . . . . . . . 57
APPENDIX C — FAN PERFORMANCE . . . . . . . . . . . 59
APPENDIX D — WIRING DIAGRAMS . . . . . . . . . . . . 84
APPENDIX E — LOW AMBIENT CONTROL 
SENSOR LOCATION . . . . . . . . . . . . . . . . . . . . . . . 96
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . CL-1

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can be
hazardous due to system pressure and electrical components. Only
trained and qualified service personnel should install, repair, or
service air-conditioning equipment. Untrained personnel can per-
form the basic maintenance functions of replacing filters. Trained
service personnel should perform all other operations.
When working on air-conditioning equipment, observe precau-
tions in the literature, tags and labels attached to the unit, and other
safety precautions that may apply. Follow all safety codes. Wear
safety glasses and work gloves. Use quenching cloth for unbrazing
operations. Have fire extinguishers available for all brazing opera-
tions.
Follow all safety codes. Wear safety glasses and work gloves. Use
quenching cloth for brazing operations. Have fire extinguisher
available. Read these instructions thoroughly and follow all warn-
ings or cautions attached to the unit. Consult local building codes
and National Electrical Code (NEC) for special requirements.
Recognize safety information. This is the safety ALERT symbol
. When you see this symbol on the unit and in instructions or
manuals, be aware of the potential for physical injury hazards.
Understand the signal words DANGER, WARNING, and CAU-
TION. These words are used with the safety ALERT symbol.
DANGER indicates a hazardous situation which, if not avoided,
will result in death or severe personal injury. WARNING indi-
cates a hazardous situation which, if not avoided, could result in
death or personal injury. CAUTION indicates a hazardous situa-
tion which, if not avoided, could result in minor to moderate injury
or product and property damage. IMPORTANT is used to ad-
dress practices not related to physical injury. NOTE is used to
highlight suggestions which will result in enhanced installation,
reliability, or operation.
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
Before performing service or maintenance operations on unit,
LOCKOUT/TAGOUT the main power switch to unit.
Electrical shock and rotating equipment could cause severe
injury.
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury or
death.
Units with convenience outlet circuits may use multiple
disconnects. Check convenience outlet for power status before
opening unit for service. Locate its disconnect switch, if
appropriate, and open it. Lock-out and tag-out this switch, if
necessary.
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
R-410A refrigerant systems operate at higher pressures than
standard R-22 systems. Do not use R-22 service equipment or
components on R-410A refrigerant equipment.
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in death, serious
personal injury and/or property damage.
Never use air or gases containing oxygen for leak testing or for
operating refrigerant compressors. Pressurized mixtures of air
or gases containing oxygen can lead to an explosion.
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in death, serious
personal injury and/or property damage.
Never use non-certified refrigerants in this product. Non-
certified refrigerants could contain contaminates that could
lead to unsafe operating conditions. Use ONLY refrigerants
that conform to AHRI Standard 700.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in reduced unit
performance or unit shutdown.
High velocity water from a pressure washer, garden hose, or
compressed air should never be used to clean a coil. The force
of the water or air jet will bend the fin edges and increase
airside pressure drop.
IMPORTANT: Lockout/Tag-out is a term used when electri-
cal power switches are physically locked preventing power
to the unit. A placard is placed on the power switch alerting
service personnel that the power is disconnected.
2
WARNING
WARNING
WARNING
WARNING
CAUTION