York YUHC 18-60 - Manual (Page 20)

20
ENGLISH
DEFROSTING OPERATION (Available for heating only)
1. Condition to start defrosting: Units will switch to defrosting
mode when either of the following conditions is met.
a. Unit has been running under T3 < 0ºC for 40
minutes and T3 < -3ºC for 3 minutes.
b. Unit has been running at high temperature protection
mode* for 90 minutes. (*High temperature
protection mode: when coil temperature of indoor
unit reaches 55°C, outdoor unit will turn off external
unit fan but still keep compressor running).
2. Condition to stop defrosting: Units will switch back to
heating mode when either of the following conditions
is met.
a. Unit has been running at defrosting mode for 10
minutes.
b. T3 > 20 ºC
Remark: T3 is coil temperature of outdoor units.
T3 (°C)
3 min
40 min
Heating mode Defrosting mode
Time
Elapsed
(min)
Starting Defrosting Mode under condition a.
SERVICE AND MAINTENANCE
The units are designed to operate for long periods of time with a minimum of maintenance. However, the following
operations must be performed regularly.
COMPONENT MAINTENANCE OPERATIONS RECOMMENDED FREQUENCY
Air filter 1 - Clean with a vacuum cleaner or tap gently
then wash in warm water (40°C) with a mild
detergent.
2 - Rinse and dry before replacing on unit.
3 - Never use petrol, alcohol or any other chemi-
cal product.
Every month or more often if
necessary.
Unit casing 1 - Remove dust from the front panel with a soft
duster or wipe a damp cloth with a mild soap
solution.
2 - Never use petrol, alcohol or any other chemi-
cal product.
Every month or more often if
necessary.
Drain pan and evacu-
ation piping
1 - Clean and check for obstructions. Each season before start up.
Indoor / Outdoor coils 1 - Check condition and remove dust from be-
tween coil fins.
Each season before start up.
Compressor 1 - No maintenance required. —
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