Refrigerant Charging; Maintenance - Carrier 07KHP Installation Manual

REFRIGERANT CHARGING

CAUTION
TO PREVENT PERSONAL INJURY, WEAR SAFETY GLASSES
AND GLOVES WHEN HANDLING REFRIGERANT. DO NOT
OVERCHARGED SYSTEM. THIS CAN CAUSE COMPRESSOR
FLOODING.
The 07KHP units are packed with refrigerant holding charge only.
Proper refrigerant charge is determine using Superheat method.
IMPORTANT
For accurate system performance, charge by superheat method as
shown in table 6 and 7.
To check and adjust charge, follow the following procedures:
1. Operate unit for a minimum of 30 minutes before checking
charge.
2. Measure suction pressure by attaching a gauge to suction
line service port.
3. Measure suction line temperature by attaching a service
thermometer to unit suction line near suction valve. Insulate
thermometer for accurate readings.
4. Measure entering water temperature with a second
thermometer.
5. Measure indoor coil air inlet wet-bulb temperature with a sling
psychrometer.
6. Refer to table 4. Find entering water temperature and wet-
bulb temperature entering indoor coil. At this intersection,
note the superheat.
7. Refer to table 5. Find superheat and temperature and suction
pressure, note suction line temperature.
8. If unit has higher suction line temperature than charted
temperature add refrigerant until charted temperature is
reached.
9. If unit has lower suction line temperature than charted
temperature, bleed refrigerant until charted temperature is
reached.
10. If entering water temperature or pressure at suction line
changes, charge to new suction line temperature indicated on
chart.
11. This procedure is valid independent of indoor air quantity.

MAINTENANCE

CAUTION
BEFORE PERFORMING RECOMMENDED MAINTENANCE, BE
SURE UNIT MAIN POWER SWITCH IS TURNED OFF. FAILURE
TO DO SO MAY RESULT IN ELECTRIC SHOCK OR INJURY.
Remove unit's access panels for internal servicing and maintenance
LUBRICANT
Compressor contains factory oil charge. Replace oil when lost. See
table 3 for oil recharge and refer to Carrier Manual Chapter 1, page 1-21
for oil recharging procedure.
7
CLEANING HEAT EXCHANGER
Use a tank with 5% phosphoric acid. Pump the cleaning liquid through
the plate heat exchanger at 1.5 times normal flow rate for optimum
cleaning, preferably in back flush mode. Then, rinse with large amount
of fresh water to get rid of all the acid before starting up the system
again. Clean at regular interval.
TABLE 4 AIR AND WATER LIMITS
LIMITS
AIR
Min. Ambient Air
Rated Ambient Air
Max. Ambient Air
Min. Entering Air at Evap
Rated Entering Air, DB/WB
Max Entering Air, DB/WB
WATER
Min. Entering Water
Normal Entering Water
Max Entering Water *
*
At maximum water flow conditions only as shown on Table 5
below
TABLE 5 WATER FLOW LIMITATIONS
UNIT MODEL NO. - 07KHP
013
018
024
040
060
090
NOTE: Water flow must be sufficient to obtain a maximum 10F
temperature rise across the water-to-refrigerant heat exchanger when
operating in the cooling mode. Water flow rates greater than 4.0 GPM
per nominal ton or water velocities of 10 ft/sec or more may cause
erosion damage to the water-to-refrigerant heat exchanger.
.
STANDARD TEMPERATURE
(C)
21
27
43
21
27/19
32/23
(C)
15
29.5
35
MAX / MIN L/S (GPM)
0.25 / 0.1
(4 / 1.5)
0.38 / 0.14
(6 / 2.3)
0.5 / 0.19
(8 / 3)
0.76 / 0.28
(12 / 4.5)
1.26 / 0.47
(20 / 7.5)
1.89 / 0.72
(30 / 11.5)