ADJUSTMENTS AND CHECKOUT
and associated flame safeguard controls.
Move the detector and
sight
pipe around to sight the flame
at various positions and angles. Try to get a maximum steady
meter reading. The signal must be above the minimum
acceptable current/voltage listed in Table 6.
Measure the
signal for the pilot alone, the main
burner flame alone, and both together (unless monitoring
only the pilot
when using an intermittent pilot, or only
burner
flame
when using direct spark ignition). Also
measure the flame signal at high and low firing rates and
while modulating in between (as applicable). With the detec-
tor in its final position, all required
signals must be
steady and as specified in Table
6. If you
cannot obtain the
proper signals, refer to the Troubleshooting section.
Fig.
flame Signal.
PLUG-IN FLAME
SIGNAL AMPLIFIER
I
SELECTOR
TEST
SWITCH,
196146 METER
CONNECTOR
RED CONNECTOR
CK CONNECTOR
M E T E R ‘
LEAD
El 208
Fig.
BCS 7700 Flame Safeguard
Control flame signal voltage.
PROBES
7700
CHASSIS MODULE
Fig.
7800 SERIES Flame
Safeguard Control flame signal voltage.
TABLE 6-FLAME SIGNAL
Minimum Maximum Minimum Maximum
Flame
Acceptable Expected Acceptable
Expected
Signal Steady Current Current Steady Voltage
Voltage
Amplifier Flame Safeguard Control (microamp) (microamp)
2.25 5.0
3.5 5.0
4.0 5.5
BCS 7700 2.2
4.98
1.25 5.0
1.25 5.0
60-2306-5