Ducane 13HPD-018-230, Инструкция по эксплуатации, Страница: 20 / 24

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BLOCK OUTDOOR COIL: [sometimes necessary
with lower temperatures] Use cardboard or plastic
sheet to restrict the airflow through the outdoor coil to
achieve pressures from 325−375 psig (2240−2585
kPa).
Higher pressures are needed to check charge.
Block equal sections of air intake panels and move
coverings sideways until the liquid pressure is in the
above noted ranges.
1. Confirm proper airflow across coil using figure 16.
2. Compare unit pressures with table 3, Normal Operating Pressures .
3. Set thermostat to call for heat (must have a cooling load between 70-80ºF
(21−26ºC).
4. Connect gauge set.
5. Measure outdoor ambient temperature.
6. When heat demand is satisfied, set thermostat to call for cooling.
7. Allow temperatures and pressures to stabilize.
NOTE − If necessary, block outdoor coil to maintain 200−250 psig.
8. Record liquid line temperature (Position temperature sensor on liquid line near
liquid line service port.) :
LIQº = ______
9. Measure liquid line pressure and use the value to determine saturation
temperature:
SATº = ______
10. Subtract to determine subcooling (SCº):
SATº_____ − LIQº _____ = SCº _____
11. Compare results with table below.
12. If value is greater than shown, remove refrigerant; if less than shown, add
refrigerant.
13. If refrigerant is added or removed, retest using approach method.
Outdoor Ambient Temperature is 65ºF
(18.3ºC) or BELOW
SCº (Subcooling) Values (F:+/−1.0° [C: +/−0.6°])
Model −018 −024 −030 −036 −042
−048 −060
°F (°C)* 6 (3.3) 11 (6) 8 (4.4) 6 (3.3) 6 (3.3) 4 (2.2) 9 (5)
NOTE − For best results, use the same electronic thermometer to check both outdoor-ambient and liquid-line temperatures. *F: + /
−1.0°; C: + / −0.5°
Figure 17. HCFC−22 Subcooling TXV Charge
Outdoor Ambient Temperature 66ºF
(18.9ºC) or ABOVE .
1. Confirm proper airflow across coil using figure16.
2. Compare unit pressures with table 3, Normal Operating Pressures .
3. Connect gauge set.
4. When heat demand is satisfied, set thermostat to call for cooling.
5. Allow temperatures and pressures to stabilize.
6. Record outdoor ambient temperature:
AMBº =_________
7. Record line temperature:
LIQº = __________
8. Subtract to determine approach (APPº):
LIQº_____ − AMBº _____ = APPº_____
9. Compare results with table below.
10. If value is greater than shown (high approach), add refrigerant; if less than shown
(liquid temperature too close to ambient temperature, low approach), remove
refrigerant.
11. If refrigerant is added or removed, retest to confirm that unit is properly charged.
APPº (Approach) Values(F:+/−1.0° [C: +/−0.6°])
Model −018 −024 −030 −036 −042
−048 −060
°F (°C)* 7 (3.9) 8 (4.4) 9 (5) 13 (7.2) 7 (3.9) 9 (5) 7 (3.9)
NOTE − For best results, use the same electronic thermometer to check both outdoor-ambient and liquid-line temperatures. *F: + /
−1.0°; C: + / −0.5°
Figure 18. HCFC−22 Approach TXV Charge