Reznor YDHA - Page 44

Form O-Y, PN 273647R5, Page 44
General Refrigeration Circuit (cont'd)
SYMPTOM POSSIBLE CAUSE REMEDY
F. Noisy unit
operation.
1. Blower rotational noise. &KHFNEORZHUPRWRUDQGGULYHIRUIDXOW\DGMXVWPHQWRUQRLV\
bearings, loose parts, and/or blower out of balance.
2. Air noise. &KHFNGXFWZRUN$LUYHORFLW\WRRKLJK
&KDWWHULQJFRQWDFWRU &KHFNIRUDGHTXDWHFRQWUROYROWDJHFKHFNIRUVKRUWVRUEUHDNV
check contact points.
4. Tubing rattle. 4. Dampen by taping or clamping, carefully bend tubing away from
contact when possible.
G. High suction
pressure.
1. Excessive load on evaporator coil. &KHFNVXSHUKHDW3DUDJUDSK&KHFNIRUKLJKHQWHULQJZHW
EXOEWHPSHUDWXUH&KHFNIRUH[FHVVLYHDLU
&RPSUHVVRULVXQORDGHG &KHFNKHDGSUHVVXUH&KHFNWKHUPDOH[SDQVLRQYDOYH,IYDOYHLV
QRWIXQFWLRQLQJSURSHUO\FKHFNSUHVVXUHGURSDFURVV¿OWHUGULHU
3. Expansion valve bulb not secured to
suction line or valve defective.
&KHFNWKHWKHUPDOH[SDQVLRQYDOYHHQVXUHEXOELVDWWDFKHG
properly and insulated
H. High
discharge
pressure.
1. Refrigerant overcharge &KHFNVXEFRROLQJ3DUDJUDSK$GMXVWUHIULJHUDQWFKDUJH
2. Thermal expansion valve setting &KHFNVXSHUKHDWDQGDGMXVWYDOYHDVQHHGHG.
2. Air inlet to condenser dirty or obstructed. &KHFNIRUSURSHUFOHDUDQFHVDQGSRVVLEOHDLUUHFLUFXODWLQJ
&RQGHQVHUIDQPRWRUGHIHFWLYH &KHFNFRQGHQVHUIDQPRWRUV
I. Suction
pressure is too
low.
1. Refrigerant undercharge. &KHFNVXEFRROLQJ3DUDJUDSK$GGUHIULJHUDQWDVQHHGHG
2. Thermal expansion valve setting &KHFNVXSHUKHDWDQGDGMXVWYDOYHDVQHHGHG
3. Blower running backward. 3. Interchange any two wires from 3 phase disconnect.
/RRVHEORZHUSXOOH\RUEHOWV &KHFNGULYHSXOOH\DOLJQPHQWDQGEHOWWHQVLRQ
'LUW\¿OWHU &KHFN¿OWHUDQGHYDSRUDWRUFRLO
7RROLWWOHDLUÀRZRUORZHQWHULQJDLU
temperature.
&KHFNDLUÀRZDQGHQWHULQJDLUZHWEXOEFRQGLWLRQV
7. Restriction in suction or liquid line. &KHFNUHIULJHUDQWFLUFXLWIRUUHVWULFWLRQ
J. Head
Pressure too
low.
,QVXI¿FLHQWUHIULJHUDQWFKDUJH &KHFNVXEFRROLQJ3DUDJUDSK&KHFNIRUOHDN5HSDLUDQG
add refrigerant.
2. Defective or improperly adjusted
expansion valve.
&KHFNVXSHUKHDW3DUDJUDSKDQGDGMXVWWKHUPDOH[SDQVLRQ
valve.
/RZVXFWLRQSUHVVXUH 3. See “I. Suction pressure too low” above.
4. Defective compressor. 4. See "G. High suction pressure” above.
.&RPSUHVVRU
short cycles..
1. Improper refrigerant charge. &KHFNVXEFRROLQJDQGVXSHUKHDW3DUDJUDSK
2. Defective high or low pressure control. &KHFNKLJKRUORZSUHVVXUHVZLWFK
/LTXLGÀRRGEDFN 3. Possible tight bearings, see above.
4. Defective expansion valve. &KHFNVXSHUKHDWDQGWKHUPDOH[SDQVLRQYDOYH
5. Poor air distribution. &KHFNGXFWZRUNIRUUHFLUFXODWLQJ
6. High discharge pressure. 6. See “H. High discharge pressure” above.
/HDNLQJGLVFKDUJHYDOYHVLQFRPSUHVVRU 7. See “G. High suction pressure” above.
/5XQQLQJ
cycle is too
long or unit
operates
continuously..
1. Refrigeration undercharged. &KHFNVXEFRROLQJ3DUDJUDSKDQGDGGUHIULJHUDQW
'LUW\¿OWHURUHYDSRUDWRUFRLO &KHFN¿OWHUFRLODQGDLUÀRZ&OHDQDQGRUUHSODFH
3. Dirty or clogged condenser coil. &KHFNFRLODQGDLUÀRZ&OHDQ
4. Air or other non-condensables in system. &KHFNHTXDOL]HGKLJKVLGHSUHVVXUHZLWKHTXLYDOHQWRXWGRRU
temperature.
5. Defective compressor. 5. See “G. High suction pressure” above.
6. Restriction in suction and liquid line. &KHFNIRUUHVWULFWLRQVLQUHIULJHUDQWFLUFXLW
&RQWUROFRQWDFWVVWXFN &KHFNZLULQJ
M. Supply air
temperature is
too high.
1. Refrigerant undercharge or leak in
system.
&KHFNVXEFRROLQJ 3DUDJUDSK&KHFNIRUOHDN5HSDLUDQG
add refrigerant.
2. Evaporator plugged with dirt or ice. &KHFNHYDSRUDWRUDLUÀRZDQG¿OWHU&OHDQ
3. Improperly adjusted or defective
expansion valve.
&KHFNVXSHUKHDW3DUDJUDSKDQGDGMXVWWKHUPDOH[SDQVLRQ
YDOYH&KHFNH[SDQVLRQYDOYHEXOESODFHPHQWDQGLQVXODWLRQ
4. Defective compressor. &KHFNFRPSUHVVRUIRUSURSHURSHUDWLRQ
5. High discharge pressure. 5. See “H. High discharge pressure” above.
$LUÀRZLVWRRKLJK &KHFNH[WHUQDOVWDWLFSUHVVXUH
N. Supply air
temperature is
too low.
$LUÀRZLVWRRORZ &KHFNHYDSRUDWRUFRLOFKHFN¿OWHUVFKHFNIRUFORVHGGDPSHUVRU
JULOOVFKHFNGULYHIRUORRVHSDUWVEHOWVRUPLVDOLJQPHQWDQGFKHFN
external static pressure.
2. Return air temperature too low. &KHFNHQWHULQJDLUZHWEXOEFRQGLWLRQV
2/LTXLGOLQH
is too hot.
1. Refrigerant undercharge. &KHFNVXEFRROLQJ
2. High discharge pressure. 2. See H. above.
7.0 Troubleshooting (cont'd)
7.1 Troubleshooting - Refrigeration (cont'd)