Greenheck Amplifier for 7800 Series Relay Module - Manual (Page 7)

R7824, R7847, R7849, R7861, R7886 AMPLIFIERS FOR 7800 SERIES RELAY MODULES
65-0109—6 7
CAUTION
Equipment Damage Hazard.
Improper wiring can destroy ultraviolet
sensing tube.
Carefully follow polarity sensitive wiring instructions for the
C7027, C7035, C7044, C7012, C7024, C7061 and C7076.
Reversing the leadwires, even momentarily, can destroy
the ultraviolet sensing tube.
1. Connect blue leadwire from detector to terminal F and
white leadwire from C7027/C7035/C7044/C7061 to
terminal G.
2. Connect blue leadwire from detector to terminal F and
yellow leadwire from C7012/C7024 to terminal G.
3. Follow lightoff Instructions for applicable 7800 SERIES
Relay Module.
Measuring Flame Signal
With Keyboard Display Module
Consult Instructions for applicable 7800 SERIES Relay
Module or Keyboard Display Module.
Measuring Flame Signal
with a Volt Ohmmeter
Two test jacks, positive and negative (Com) are accessible on
the top of the amplifier when plugged into the 7800 SERIES
Relay Module. These jacks are provided for monitoring flame
signal strength. Use a one megohm/volt meter to measure the
flame signal strength. Connect the positive meter lead (red) to
the positive (+) amplifier test jack and the negative meter lead
(black) to the negative (-) amplifier test jack. The test jacks
use standard 0.180 inch diameter voltmeter probes. A
minimum 1.25 Vdc flame signal is required.
The flame signal for the pilot alone, the main burner flame
alone, and both together must be steady and a minimum of
1.25V. If the flame signal is unsteady, or less than the
minimum acceptable voltage, check the flame detector
installation and circuitry in the following procedure.
1. Check the supply voltages at terminals (L1) and L2 (N).
Make sure the master switch is closed, connections are
correct, and the power supply is of the correct voltage
and frequency and is sinusoidal.
2. Check the detector wiring for defects including:
a. Incorrect connections.
b. Wrong type of wire.
c. Deteriorated wire.
d. Open circuits.
e. Short circuits.
f. Leakage paths caused by moisture, soot or
accumulated dirt.
3. For a flame rod, make sure:
a. There is enough ground area.
b. The flame rod is properly located in the flame.
c. Temperature at the flame rod insulator is no
greater than 500
°
F (260
°
C).
4. For all optical detectors, clean the detector viewing
window, lens, and inside of the sight pipe as applicable.
5. With the burner running, check the temperature at the
detector. If it exceeds the detector maximum rated
temperature:
a. Add a heat block to stop conducted heat traveling
up the sight pipe.
b. Add a shield or screen to reflect radiated heat.
c. Add cooling (refer to sight pipe ventilation in the
detector Instructions).
6. Make sure that the flame adjustment is not too lean.
7. Make sure the optical detector is properly sighting the
flame.
8. If necessary, resight or reposition the detector.
9. If you cannot obtain proper operation, replace the plug-
in amplifier.
10. If you cannot yet obtain proper operation, replace the
flame detector.
IMPORTANT
If you make any changes to the flame detection
system, repeat all required Checkout tests in
Checkout section of the Instructions for the
applicable 7800 SERIES Relay Module.