Carrier XRV Spécifications télécharger pdf (Page 73)

Table 13 — Control Test Menu Functions

*Diffuser tests function only on size 4 and 5 compressor with diffuser

control enabled.

NOTE: During any of the tests, an out-of-range reading will have an

asterisk (*) next to the reading and a message will be displayed if

diffuser control is enabled.

PRESSURE TRANSDUCER CALIBRATION — The

transducers measuring single pressure values (such as condens-

er and evaporator pressure) are calibrated individually, while a

pair of transducers measuring a pressure differential (OIL/

PUMP DELTA P, CONDENSER WATER DELTA P,

CHILLED WATER DELTA P) are calibrated together as a dif-

ferential. In units with ICVC controllers, transducers for

sensing water side flow are not provided as standard. These

readings can be viewed and calibrated from the COMPRESS

and HEAT_EX screens on the ICVC controller.

Each transducer or transducer pair can be calibrated at two

points: zero (0 psig or 0 kPa) and “high end” (between 25 and

250 psig, or between 173 and 1724 kPa). It is not usually

necessary to calibrate at initial start-up. However, at high

altitude locations, recalibration may be necessary to ensure the

proper refrigerant temperature-pressure relationship.

Zero Point Calibration

— Shut down the compressor, and

cooler and condenser pumps. There must be no water flow

through the heat exchangers, but these systems must be filled.

For differential pairs, leave the transducers installed. For single

value transducers, disconnect the transducer’s electrical cable,

remove the sensor from its Schrader fitting, then reconnect the

cable.

NOTE: If the cooler or condenser vessels are at 0 psig (0 kPa)

or are open to atmospheric pressure, the transducers can be

calibrated for the zero point without removal.

Access the HEAT_EX or COMPRESS screen under the

STATUS menu, and view the particular transducer reading.

(OIL PUMP DELTA P is in the COMPRESS screen; all others

are in HEAT_EX.) If the displayed reading is not 0 psi (0 kPa),

press the key to highlight the associated line in the

display, then the key. (For zero point calibration, the

and keys have no effect.) The val-

ue should change to 0.0.

If the ICVC fails to accept the zero point calibration, the

value will not change to 0.0 and the display will show “Higher

Force In Effect”. This indicates that the sensor voltage is out of

the acceptable range. For each single value transducer there are

3 terminals at the CCM: 0 vdc (low), “sensor” voltage, and

5.00 vdc (high). With a base supply voltage of 5.00 volts, the

acceptable range of voltage taken between the low and sensor

terminals for zero point calibration is 0.40 to 0.55 v. For each

transducer differential pair there are two 3-terminal sets at the

CCM. With a base supply voltage of 5.00 volts, the acceptable

range of voltage taken between the sensor terminal for the high

end transducer (water inlet or oil pump discharge) and the

sensor terminal for the low end transducer (water outlet or oil

sump) for zero point calibration is –0.065 to +0.085 v. If this

occurs with a differential pair, one possible remedy is to swap

the high end (e.g., inlet) and low end (e.g., outlet) transducers.

In most cases this puts the sensor voltage within the acceptable

range.

High End Calibration

— High end calibration can be per-

formed between 25 and 250 psig (173 and 1724 kPa), compar-

ing the pressure readings in the ICVC display to an accurate re-

frigeration gage. While it normally will have a negligible ef-

fect, it may improve transducer accuracy over the full pressure

range. High end calibration is not recommended for transducer

differential pairs. Pressure can be provided by attaching a reg-

ulated 250 psig (1724 kPa) pressure source, such as from a ni-

trogen cylinder, to the transducer.

Access the HEAT_EX screen under the STATUS menu,

and the CONDENSER PRESSURE or EVAPORATOR

PRESSURE to the reference pressure gage. To change the dis-

played reading, press the key to highlight the associ-

ated line in the display, then the or

key to set the new value, then the key. Generally, the

value can be changed to any value within ±15% of a nominal

value.

NOTE: Prior calibrations may have shifted the present

pre-calibration value from the center of this range. In this case,

the limit of acceptable new values will be less than 15% in one

direction.

TESTS TO BE

PERFORMED

DEVICES TESTED

1. CCM Thermistors Entering Chilled Water

Leaving Chilled Water

Entering Condenser Water

Leaving Condenser Water

Evap Saturation Temp

Comp Discharge Temp

Comp Thrust Brg Temp

Oil Sump Temp

Comp Motor Winding Temp

Spare Temperature 1

Spare Temperature 2

Remote Reset Sensor

2. CCM Pressure

Transducers

Evaporator Pressure

Condenser Pressure

Oil Pump Delta P

Chilled Water Delta

Condenser Water Delta P

Transducer Voltage Ref

Humidity Sensor Input

Relative Humidity

3. Pumps Oil Pump — Confirm Pressure

Chilled Water — Confirm Flow and Delta P

Condenser Water — Confirm Delta P

4. Discrete

Outputs

Oil Heater Relay

Hot Gas Bypass Relay

Tower Fan Relay Low

Tower Fan Relay High

VFD Coolant Solenoid

Alarm Relay

Shunt Trip Relay

5. IGV & SRD

Actuator

Open/Close

If present, split ring diffuser will operate in

coordination with the guide vanes per con-

figured schedule.

6. Head Pressure

Output

Increase/Decrease 4-20 mA output

7. Diffuser Actuator* Open/Close (independent of guide vanes)

8. Pumpdown

Lockout

When using pumpdown/lockout, observe

freeze up precautions when removing

charge:

Instructs operator which valves to close and

when.

Starts chilled water and condenser water

pumps and requests flow confirmation.

Monitors

Evaporator pressure

Condenser pressure

Evaporator temperature during

pumpout procedures

Turns pumps off after pumpdown.

Locks out compressor.

9. Terminate

Lockout

Starts pumps and monitors flows.

Instructs operator which valves to

open and when.

Monitors

Evaporator pressure

Condenser pressure

Evaporator temperature during

charging process

Terminates compressor lockout.

10. Guide Vane

Calibration

Automatic, displays guide vane position sig-

nal voltage. This test is required before first

startup with new Actuator or Controller.

SELECT

ENTER

INCREASE

DECREASE

SELECT

INCREASE

DECREASE

ENTER

1 2 ... 68 69 70 71 72 73 74 75 76 77 78 ... 189 190

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Carrier XRV Spécifications Page 73

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