York SSS 14L-B, Руководство по эксплуатации

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JOHNSON CONTROLS
38
FORM 160.00-O2
ISSUE DATE: 04/30/2019
SECTION 8 – MAINTENANCE AND TROUBLESHOOTING
8. After the chiller has been running for one min-
ute, measure the voltage across the SCR. The
voltage should measure between .70 – 2.0 VAC.
The voltage should remain stable. If the volt-
age is not stable, or is higher than 9.0 VAC,
there could be a problem with the gate driver
on the Logic/Trigger Board, or the SCR is not
latching on. In the case of the SCR not latch-
ing on, this is typical of older starters. Verify
each SCR pole by moving the meter to L-2 and
T-2, and L-3 and T-3. This test verifies the opera -
tion of the starter. If these voltages are correct, then
the problem is most likely other than the starter.
VERIFY FALSE PHASE CURRENT
IMBALANCE
Use this section if the current imbalance is not real, but
is a reporting problem.
1. Verify that the OptiView Control Center has the
correct model of starter selected. If not, verify
wiring of the J1 connector. Refer to the current
scaling section in this form.
2. If this is not the source of the problem, continue.
3. Remove main input power to the starter.
4. Set ohm meter to Rx1 range. If the ohm meter is a
digital model, and has a diode test scale, place the
meter in the diode test mode.
5. Remove the J1 connector, and measure the resis-
tance of the three output CTs. The resistance value
will vary depending on the model of the starter.
MODEL STARTER CT RESISTANCE RANGE
7L 2.4 – 4.3 OHMS
14L 5.0 – 7.3 OHMS
26L 8.0 – 16.8 OHMS
33L 10.7 – 22.0 OHMS
6. If this is not the source of the problem, continue.
7. Measure resistance across J1 pin 1-2. A resistance
value of 3.0 ohms should be displayed on your
meter. This resistor is a 0.1% tolerance compo-
nent. If it is out of tolerance, replace the Logic/
Trigger Board. Repeat this step with J1 pin 3-4,
and J1 pin 5-6.
8. Reconnect the J1 connector.
9. If this is not the source of the problem, continue.
10. Start the chiller.
11. Connect another current measuring device around
the output wire to the motor.
12. Compare the three phase current from the
OptiView Control Center to the three measured
currents.
13. Replace the CT in the phase in which the current
does not measure correctly.
REMOVING SCR ASSEMBLIES
Refer to the Replacement Parts List Form 160.00-RP3
for replacement SCR assembly kit part numbers.
1. Remove AC power from system. If the starter has
a circuit breaker, place it in the off position.
2. Drain coolant as directed in the Fill Cooling Loop
Section.
3. Loosen the hose clamps and remove the hoses
from the defective heatsink assembly.
4. Place tape over the hose barbs, so that the coolant
does not leak into the cabinet of the starter.
5. Remove all electrical connections from the Logic/
Trigger Board. Remove Logic/Trigger Board as-
sembly by removing 4 panel mounting screws and
the 6 screws holding the gate wire clamps.
6. Disconnect the thermistor wire connector for the
failed SCR (J/P16, J/P17, J/P18).
7. Mark and then remove the output wires to the mo-
tor. Fold out of the way if possible.
8. Remove the current transformer mounting bracket
by removing the four screws on the back of the
starter. Move CT assembly out of the way.
9. Remove the two bolts connecting the SCR assem-
bly to the bus bar.