Emerson Process Management 760004-A - Manual (Page 63)

Instruction Manual
760004-A
February 2002
Rosemount Analytical Inc. A Division of Emerson Process Management Maintenance and Service 4-25
Model NGA 2000 HFID
a. LON/Power Module
1. Disconnect wiring connectors, note
locations.
2. Refer to Figure 4-20. From the out-
side of the front panel, remove the
two mounting screws.
3. Install replacement module in reverse
order.
b. LED Indicator Assembly
1. Disconnect wiring connector, note lo-
cation.
2. Refer to Figure 4-20. From the inside
of the front panel, remove the two hex
nuts securing LED indicator assembly
to front panel. Remove indicator as-
sembly and o-rings (four).
3. Inspect o-rings for damage, replace if
necessary. Install o-rings on re-
placement indicator assembly, mount
assembly on mounting studs with hex
nuts.
4. Re-connect wiring connector.
c. Manual Ignite Toggle Switch
1. Disconnect wiring connector, note lo-
cation.
2. Refer to Figure 4-20. From the out-
side of the front panel, remove the
toggle switch seal.
3. Pull the switch and o-ring out from in-
side the front panel.
4. Inspect o-ring for damage, replace if
necessary. Install o-ring on replace-
ment switch, insert through front
panel from the inside.
5. Install switch seal.
6. Re-connect wiring connector.
d. Burner Air Sensor
1. Disconnect wiring connector, note lo-
cation.
2. Using an open-end wrench to hold the
sensor fitting while using another
open-end wrench to remove the sen-
sor.
3. Replace the Teflon pipe thread tape
on the treads of the sensor fitting.
4. Install sensor onto sensor fitting.
5. Re-connect wiring connector.
e. Fuel Sensor
1. Disconnect wiring connector, note lo-
cation.
2. Using an open-end wrench to hold the
sensor fitting while using another
open-end wrench to remove the sen-
sor.
3. Replace the Teflon pipe thread tape
on the treads of the sensor fitting.
4. Install sensor onto sensor fitting.
5. Re-connect wiring connector.
f. Burner Air and Fuel Regulators
1. Disconnect the two tubes and the
sensor fitting on the rear of the regu-
lator, note locations.
2. Replace the Teflon pipe thread tape
on the threads of the sensor fitting.
3. Remove the regulator and o-ring.
4. The replacement regulator comes
with two panel mounting nuts, remove
both and discard one of them.