TM 10-4520-259-13&P
j.
Unit maintenance has determined that ignition takes place momentarily but system shuts down
immediately after ignition. With multimeter set for dc operation, press reset button (9), check voltage at test
points (16, black) and (17, red). If voltage is not 4 to 6 V dc, replace the UV scanner as described in Remove
steps.
k.
Unit maintenance has determined that ignition does not occur after pressing reset pushbutton but
buzzer sounds. With multimeter set for ac operation, check for 120 Vac at test points #2 and #3 after pressing
reset button (9). If voltage is 0, replace the flame safeguard control (6).
REMOVE
a.
Loosen two screws (7) and flame safeguard control (6).
b.
Tag and disconnect two wires (10) and (11) from terminal
S1 and S2 on base terminal board (8).
c.
Disconnect UV scanner (12) at burner head assembly (13) and remove conduit nut (14). Pull UV
scanner and wires from the conduit (15).
INSTALL
a.
To install the UV scanner (12), insert UV scanner wires (10) and (11) into conduit (15). Screw conduit
nut (14) to UV scanner (12) until connection is tight.
b.
Screw UV scanner (12) to scanner tube at burner head (13). Connect two wires (10) and (11) to
terminals S1 and S2 on base terminal board (8).
c.
Install flame safeguard control (6) and secure with two screws (7).
d.
Close lid (1) on control box and turn off power switch.
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