Carrier 5F - Manual (Page 38)

HEATING A COOLING
5F,H
Open-Drive Compressors
TROUBLESHOOTING (cont)
TROUBLE/SYMPTOM PROBABLE CAUSE REMEDY
System noises, (cont) Unit foundation improperly isolated. Isolate foundation.
Improper support or isolation of piping. Use correct piping techniques and support
piping with suitable hangers.
Slugging from refrigerant feedback. Check expansion valve setting. Check
thermal bulb looseness and correct
location. See Carrier System Design
Manual, Part 3 for standard piping
techniques.
Hydraulic knock from excessive oil in
circulation. Remove excess oil. Check expansion
valve for floodback.
Defective valve lifter mechanism (noise
level varies with unloading). Replace sticking filter pins. Check un­
loader fork for alignment. Check power
element for sticking piston. Check for oil
leakage at tube connection to power
element. Check amount of valve pin lift
above valve seat (0.33 in. for 5F; 0.125 in.
for 5H).
Piping vibration. Support pipes as required. Check pipe
connections.
No muffler in discharge line or improperly
located. Install muffler. Move muffler closer to
compressor.
Hissing (insufficient flow through expan­
sion valves, orclogged liquid line strainer). Add refrigerant. Clean strainer
Compressor will not unload. Capacity control valve not operating. Repair.
Unloader element sticking. Repair.
Hydraulic relay sticking. Replace control cover assembly.
Plugged pressure line to power element. Clean line.
External adjusting stem damaged. Replace.
Compressor will not load. Low oil pressure (below 35 psi). Check oil charge, switch settings.
Capacity control valve stuck open. Repair or replace.
Unloader element sticking. Repair.
Plugged or broken pressure line to power
element.
Clean or repair.
External adjusting stem damaged. Replace.
Control oil strainer blocked. Clean or replace.
Control valve bellows leaking. Remove thread protector and leak test.
Replace valve body if bellows leaks.
Pipe plug in pneumatic connection. Remove pipe plug.
Foaming in crankcase ^rom refrigerant
flooding. Check expansion valve and piping.
Hydraulic relay sticking. Replace control cover assembly.
Rapid unloader cycling. Excessive fluctuation in suction pressure
from oversized expansion valve.
Resize expansion valve.
Partially plugged control oil strainer. Clean or replace strainer.
Low oil pressure. See Trouble/Symptom — low oil pressure.
Low oil pressure. Low oil charge. Add oil.
Faulty oil gage. Check and replace.
Defective oil pressure regulator. Repair or replace.
Clogged oil suction strainer. Clean strainer.
Broken oil pump tang. Replace pump assembly.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obiigations.
Book! 2 PC111 Catalog No 530-526 PrintedinUSA Form 5F,H-11SI Pg 38 2-86 Replaces: 5F,H-9SI
Tab 2a For replacement Hems use Carrier Specified Parts.