Frick HPS 36, Руководство по установке, Страница: 37 / 54

HPS Rotary Screw Compressor Units 070.700-IOM (MAR 21)
Page 37 Maintenance
4. Ensure the voltage reading is between 1.48 VDC to
1.72 VDC at standard atmospheric pressure (14.7 psia
or 0 psig). When checking transducers at higher eleva -
tions, an allowance in the readings must be made by
subtracting approximately 0.02 VDC each 1000 ft
(304.8 m) of elevation above sea level. If PE-4 is
measured at 5000 ft (1524 m) elevation under relatively
normal weather conditions, the output voltage differs
by 0.10 VDC to read between 1.38 VDC and 1.62 VDC.
5. Isolate the oil pressure transducer PE-1 from the pack-
age and open it to atmosphere.
6. Measure the voltage of PE-1 on connector P5A (termi -
nals WHT and BLK) on the Analog Board.
7. Ensure the voltage reading is between 1.1 VDC and 1.29
VDC at standard atmospheric pressure.
8. Isolate transducer PE-2 from the package and depres -
surize.
Notice
Recover or transfer all refrigerant vapor, in ac-
cordance with local ordinances, before opening to
atmosphere.
9. Measure the voltage of PE-2 on connector P5B (termi -
nals WHT and BLK) on the Analog Board.
10. Ensure the voltage reading is between 1.1 VDC and 1.29
VDC at standard atmospheric pressure (see Step 12).
11. Because the discharge pressure, PE-3, cannot be
closed off from its sensing point (code require ments),
close all transducers from atmosphere and open them
to their sensing points so all transducers can equalize
to separator pressure.
12. Measure the voltage of PE-3 on connector P5B (termi -
nals WHT and BLK) on the Analog Board.
13. Measure the voltage of PE-1 on connector P5A (termi -
nals WHT and BLK) on the Analog Board.
14. Ensure these voltages are within 0.04 VDC of one
another.
The test is complete.
Replacing pressure transducers
1. Shut off control power.
2. Close the applicable transducer isolation valve.
Notice
To change the discharge pressure transducer (PE-3),
it is necessary to depressurize the entire compres-
sor package. Follow
General instructions for replacing
compressor unit components before performing Step
3.
Figure 38: Pressure transducer color key
CABLE COLOR CODE
PIN 1 + SUPPLY
PIN 2 DC COMMON
PIN 3 SIGNAL
CASE GND
2
3
1
3. See Figure 38 to identify wiring harness connectors.
4. Loosen screw and disconnect wiring harness connector
from transducer.
5. U nscrew the transducer using a wrench on the metal
hex at the base of the transduce r. Do not attempt to
loosen or tighten transducers by their top casing.
6. Install new transducer.
7.
Reconnect the wiring harness to the transducer.
8. Reopen the transducer isolation valve.
9. Turn on control power.
Notice
The pressure transducer is factory set. If calibration
is required, refer to
Analog Calibration Instruction in
publication 090.040-M, Quantum HD Control Panel M
Table 14: Pressure transducer conversion data
Sensor
Voltage
800 psi
Range (psig)
Low High
1.0 VAC 0.8
1.1 19.2 20.8
1.2 39.2 40.8
1.3 59.2 60.8
1.4 79.2 80.8
1.5 99.2 100.8
1.6 119.2 120.8
1.7 139.2 140.8
1.8 159.2 160.8
1.9 179.2 180.8
2.0 199.2 200.8
2.1 219.2 220.8
2.2 239.2 240.8
2.3 259.2 260.8
2.4 279.2 280.8
2.5 299.2 300.8
2.6 319.2 320.8
2.7 339.2 340.8
2.8 359.2 360.8
2.9 379.2 380.8
3.0 399.2 400.8
3.1 419.2 420.8
3.2 439.2 440.8
3.3 459.2 460.8
3.4 479.2 480.8
3.5 499.2 500.8
3.6 519.2 520.8
3.7 539.2 540.8
3.8 559.2 560.8
3.9 579.2 580.8
4.0 599.2 600.8
4.1 619.2 620.8
4.2 639.2 640.8
4.3 659.2 660.8
4.4
679.2 680.8
4.5
699.2 700.8
4.6
719.2 720.8
4.7
739.2 740.8
4.8 759.2 760.8
4.9 779.2 780.8
5.0 799.2 800.8
At 0 psig 0.968 V 1.268 V
Note: Below 0 psig measured in inches of mercury.