Trane 4TWR4 Installation And Operation Manual page 15

STEP 7 - Stabilize the system.
1. Wait 20 minutes for the system condition to stabilize between adjustments.
Note: When the Liquid Line Temperature and Gage Pressure approximately match the chart, the system
is properly charged.
2. Remove gages.
3. Replace service port caps to prevent leaks. Tighten finger tight plus an additional 1/6 turn.
STEP 8 - Verify typical performance.
Refer to System Pressure Curves in the Service Facts to verify typical performance.
STEP 9 - Record System Information for reference.
Record system pressures and temperatures after charging is complete.
Outdoor model number = _________________
Measured Outdoor Ambient = __________ º F
Measured Indoor Ambient = __________ º F
Measured Liquid Line Temp = __________ º F
14.3 Subcooling Charging Below 55º F Outdoor Temp. (In Heating Only)
The Subcooling Charging method in cooling is not recommended below 55º F outdoor temperature.
The only recommended method of charging at outdoor temperatures below 55º F is weighing in the charge in
heating mode.
STEP 1 - Determine additional charge.
Note: The nameplate charge value represents the amount of refrigerant shipped in the outdoor unit and is
compatible with 10 feet of AHRI rated refrigerant lines and the smallest AHRI rated coil.
Using the method below, find the charge associated with the additional length of tubing above 10 ft. and record it
below.
Weigh-In Method can be used for the initial installation, or anytime a system charge is being replaced. Weigh-In
Method can also be used when power is not available to the equipment site or operating conditions (indoor/outdoor
temperatures) are not in range to verify with the subcooling charging method.
18-BC95D1-5E-EN
(Example only - see Service Facts)
PRESSURE CURVES FOR 4TWR3036B1000A
TAM4A0A36S31
Cooling
INDOOR ENTERING WET BULB CURVES TOP TO BOTTOM 71,
67, 63 AND 59 DEG F.
500
450
400
350
(4) (3)
300
250
(1)
200
55 65 75 85
INDOOR ENTERING WET BULB CURVES TOP TO BOTTOM
160
71, 67, 63 AND 59 DEG F.
155
150
145
140
(5) (3)
135
130
125
120
115
(1)
110
55 65 75 85
COOLING PERFORMANCE CAN BE CHECKED WHEN THE OUTDOOR TEMP IS ABOVE 65 DEG F.
TO CHECK COOLING PERFORMANCE, SELECT THE PROPER INDOOR CFM, ALLOW PRESSURES TO STABILIZE. MEASURE INDOOR WET BULB
TEMPERATURE, OUTDOOR TEMPERATURE, DISCHARGE AND SUCTION PRESSURES. ON THE PLOTS LOCATE OUTDOOR TEMPERATURE (1);
LOCATE INDOOR WET BULB (2); FIND INTERSECTION OF OD TEMP. & ID W.B. (3); READ DISCHARGE OR SUCTION PRESSURE IN LEFT
COLUMN (4) or (5).
EXAMPLE: (1) OUTDOOR TEMP. 82 F.
(2) INDOOR WET BULB 67 F.
(3) AT INTERSECTION
(4) DISCHARGE PRESSURE IS 315 PSIG
(5) SUCTION PRESSURE IS 135 PSIG
INTERCONNECTING LINES
GAS - 3/4" O.D.
LIQUID - 3/8" O.D.
Measured Suction Line Temp = __________ º F
Liquid Gage Pressure = __________ PSIG
Suction Gage Pressure = __________ PSIG
TAM4A0A36S31
Heating
INDOOR ENTERING DRY BULB CURVES TOP TO BOTTOM 80, 70, AND 60
DEG F.
500
(2)
450
400
350
300
250
95 105 115 -5 5 15 25 35 45 55
OUTDOOR TEMPERATURE (Degree F)
INDOOR ENTERING DRY BULB CURVESTOP TO BOTTOM 80, 70, AND
160
60 DEG F.
150
140
(2)
130
120
110
100
90
80
70
60
50
40
95 105 115 -5 5 15 25 35 45 55
OUTDOOR TEMPERATURE (Degree F)
ACTUAL:
DISCHARGE PRESSURE SHOULD BE +/- 10 PSI OF CHART
SUCTION PRESSURE SHOULD BE +/- 3 PSIG OF CHART
DWG.NO. 4TWR3036B1
65
65
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