Instruction manual

31
Table 14 — Operating Limits —
50RHR,RHS,RVR,RVS,RDS Units
LEGEND
NOTE: Value in heating column is dry bulb only. Any wet bulb reading is
acceptable.
Scroll Compressor Rotation —
It is important to be
certain compressor is rotating in the proper direction. To
determine whether or not compressor is rotating in the proper
direction:
1. Connect service gages to suction and discharge pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the discharge
pressure should rise, as is normal on any start-up.
If the suction pressure does not drop and the discharge
pressure does not rise to normal levels:
1. Turn off power to the unit. Install disconnect tag.
2. Reverse any two of the unit power leads.
3. Reapply power to the unit and verify pressures are correct.
The suction and discharge pressure levels should now move
to their normal start-up levels.
When the compressor is rotating in the wrong direction, the
unit makes more noise and does not provide cooling.
After a few minutes of reverse operation, the scroll com-
pressor internal overload protection will open, thus activating
the unit lockout. This requires a manual reset. To reset, turn the
thermostat on and then off.
NOTE: There is a 5-minute time delay before the compressor
will start.
Unit Start-Up Cooling Mode
1. Adjust the unit thermostat to the warmest position.
Slowly reduce the thermostat position until the compres-
sor activates.
2. Check for cool air delivery at unit grille a few minutes
after the unit has begun to operate.
3. Verify that the compressor is on and that the water flow
rate is correct by measuring pressure drop through the
heat exchanger using P/T plugs. See Table 15. Check the
elevation and cleanliness of the condensate lines; any
dripping could be a sign of a blocked line. Be sure the
condensate trap includes a water seal.
4. Check the temperature of both supply and discharge wa-
ter. Compare to Table 16. If temperature is within range,
proceed. If temperature is outside the range, check the
cooling refrigerant pressures in Table 16.
5. Check air temperature drop across the coil when com-
pressor is operating. Air temperature drop should be
between 15 and 25 F.
Table 15 — Water Temperature Change
Through Heat Exchanger
Unit Start-Up Heating Mode
NOTE: Operate the unit in heating cycle after checking the
cooling cycle. Allow five minutes between tests for the pres-
sure or reversing valve to equalize.
1. Turn thermostat to lowest setting and set thermostat
switch to HEAT position.
2. Slowly turn the thermostat to a higher temperature until
the compressor activates.
3. Check for warm air delivery at the unit grille within a few
minutes after the unit has begun to operate.
4. Check the temperature of both supply and discharge wa-
ter. Compare to Table 16. If temperature is within range,
proceed. If temperature is outside the range, check the
heating refrigerant pressures in Table 16.
5. Once the unit has begun to run, check for warm air deliv-
ery at the unit grille.
6. Check air temperature rise across the coil when compres-
sor is operating. Air temperature rise should be between
20 and 30 F after 15 minutes at load.
7. Check for vibration, noise and water leaks.
Table 16 — Typical Unit Operating Pressures and Temperatures
LEGEND NOTES:
1. Based on nominal 400 cfm per ton airflow, 70 F EAT heating and 80/67 F
EAT cooling.
2. Cooling air and water numbers can vary greatly with changes in humidity.
3. Subcooling is based upon the head pressure at compressor service port.
AIR LIMITS COOLING (F) HEATING (F)
Min. Ambient Air 45 45
Rated Ambient Air 80 70
Max. Ambient Air 100 85
Min. Entering Air 50 40
Rated Entering Air db/wb 80/67 70
Max. Entering Air db/wb 110/83 80
WATER LIMITS
Min. Entering Water 30 20
Normal Entering Water 50-90 30-60
db — Dry Bulb
wb — Wet Bulb
WATER FLOW RATE (GPM)
COOLING
RISE (F)
HEATING
DROP (F)
Min Max Min Max
For Closed Loop: Ground Source or
Cooling/Boiler Systems at 3 gpm/ton
91248
For Open Loop: Ground Water Systems at
1.5 gpm/ton
20 26 10 17
ENTERING
WATER
TEMP (F)
(EWT)
GPM/
TON
COOLING HEATING
Suction
Pressure
(PSIG)
Discharge
Pressure
(PSIG)
Super-
heat
(F)
Sub-
cooling
(F)
Water
Temp
Rise
(F)
Air
Temp
Drop (F)
DB
Suction
Pressure
(PSIG)
Discharge
Pressure
(PSIG)
Super-
heat (F)
Sub-
cooling
(F)
Water
Temp
Drop (F)
DB
Air
Temp
Rise (F)
30
1.5 75-85 90-105 25-40 12-20 21-24 21-26 34- 39 167-186 12-16 1-4 7.6- 8.4 14-20
2.3 74-84 80- 95 25-40 11-18 13-16 21-26 37- 43 172-191 12-16 1-4 4.8- 5.6 16-22
3.0 73-83 70- 85 25-40 10-16 6-11 21-26 40- 46 177-196 12-16 1-4 3.4- 4.2 16-22
50
1.5 75-85 125-155 12-20 10-18 20-23 20-25 50- 60 180-210 10-17 1-5 10.8-11.9 23-29
2.3 74-84 120-142 12-20 9-16 12-15 20-25 53- 62 185-215 10-17 1-5 6.7- 8.1 24-30
3.0 73-83 115-138 12-20 8-14 8-12 20-25 55- 65 190-220 10-17 1-5 5.1- 5.9 25-31
70
1.5 75-85 179-198 9-16 8-15 19-22 19-24 71- 82 205-230 14-19 1-5 14.0-15.2 28-34
2.3 74-84 168-186 9-16 8-14 12-17 19-24 73- 85 210-238 14-19 1-5 9.0-10.2 30-37
3.0 73-83 158-175 9-16 8-12 7-12 19-24 76- 88 215-242 14-19 1-5 6.7- 7.9 31-38
90
1.5 75-85 229-251 9-17 8-15 18-21 17-23 85- 95 220-260 18-28 2-5 14.4-16.6 32-39
2.3 74-84 218-241 9-17 8-14 10-14 17-23 90-100 225-265 18-28 2-5 10.8-12.4 33-41
3.0 73-83 208-230 9-17 8-12 6-11 17-23 95-105 230-270 18-28 2-5 7.2- 8.3 35-42
110
1.5 77-87 280-320 8-15 10-25 17-20 15-20
2.3 76-86 270-310 8-15 10-24 9-13 15-20
3.0 75-85 260-300 8-15 10-22 5-10 15-20
DB — Dry Bulb
EAT — Entering Air Temperature