Carrier TYLER Advantage NLBN, Installation & Service Manual

Page: 19 / 27

Installation & Service Manual NLBR, NLBN, NLBS
November, 2005 Page 19
SERVICE INSTRUCTIONS
Troubleshooting Self-Contained Units (NLBS Only)
WARNING
Never work on electrically powered equipment while it is energized! Electrical shock could
cause personal injury and/or death.
TROUBLE COMMON CAUSE REMEDY
1. Unit will not run Blown fuse Replace fuse.
Low voltage Check outlet with voltmeter. Voltage
should be 115V or 220V (±10%).
Inoperative motor or Check connections.
temperature control
2. Refrigerated section Shelves overloaded; Make sure items do not block the
is too warm blocked air flow air flow.
Thermostat set incorrectly Check setting.
Pressure control set Check setting.
incorrectly
Case fans not operating Check terminal block connections.
3. Refrigerated section Thermostat set incorrectly Check setting.
too cold
Pressure control set Check setting.
incorrectly
4. Unit runs all the time Inadequate air circulation Relocate cabinet or remove obstruc-
tion. Check installation requirements.
Room temperature Ventilate room appropriately.
too warm
Thermostat set incorrectly Reset thermostat.
Refrigerant charge low Have unit serviced by a qualified
service technician.
5. Noisy operation Loose baffles Tighten or brace baffles.
Tubing contacting cabinet Move tubing.
or other tubing
Cabinet not level Level cabinet.
6. Frost or ice on Defrost clock doesn’t work Check electrical conections. Have
evaporator coil unit serviced by a qualified service
technician.
7. Water dripping from Condensate drain clogged Clear drain.
case drain
Dissipator not functioning Check electrical supply. Check
float assembly.