Nordson 303 779B, Руководство пользователя по изделию

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Troubleshooting
B 5-24
E
1998 Nordson Corporation
All rights reserved
303 779B
Issued 11/98
Manual 12-44
Use the following steps to check the blower relay.
If BLWR LED (D3) is ON
1. Measure the voltage at the blower relay from A to B. This should
measure 120 Vac.
If 120 Vac is present:
a. Check fuses and circuit breakers on the blower and reset if
necessary. If the fuses or circuit breakers open again
immediately, check the continuity of the motor circuitry for a short.
b. If fuses or breakers are good and contactor still does not
energize, the blower relay is defective.
If 120 Vac is not present:
a. Turn main power off, remove the black dust cover from connector
J8 on the SSR connector card, then turn power back ON.
NOTE: Remember to replace the dust cover.
b. Access an appropriate screen and measure at pins 6 and 7 of J8.
This should measure 120 Vac. If it does not measure 120 Vac,
the SSR connector card is defective. If it is present, the wiring is
defective.
If a zone turns on but does not control its temperature or trips the circuit
breakers, measure for 12 Vac at the 2 position of the IDC connector. If
12 Vac is not measured, the SCR controller card or the feedback card
may be defective. Use this test to check for either one of these faults.
1. In the Set-Up mode, enter a setpoint of 300 in the zone which is not
controlling its temperature or is tripping the circuit breakers.
2. The actual row of this zone should display a rising temperature value.
3. If the zone temperature is not rising, remove the ribbon cable
connector from feedback card and use an oscilloscope at pins 1
and 2 of the feedback card connector; a continuous square wave
should be seen.
S
If a square wave is not found, the feedback card is defective.
Replace the feedback card.
S
If square wave is found, then SCR controller is bad or ribbon
cable is defective. Replace the SCR connector card.
Blower Relay Check
Zone Voltage Test