20
5.
When the firing rate motor reaches its open damper position, the Hi Purge switch closes (D-8)
and the prepurge interval of 30
*
seconds is initiated. The ED510 will display:
PURGE 00:05
HIGH FIRE PURGE
If the D-8 circuit does not close, the program will hold in this position for ten minutes waiting
for it to close. If it does not, the control will lockout
6.
When the prepurge is completed, the firing rate motor is driven toward the low purge damper
position (10-12 circuit made). The ED510 will display:
PURGE 00:35
LOW FIRE PURGE
7.
Following the minimum 30 second delay (to permit the firing rate motor to get to the low fire
position), the control will wait for the low fire switch (M-D) to close. When it closes, the trial for
ignition sequence will start. If after ten minutes, the M-D circuit is not closed, the control will
lockout.
8.
The trial for ignition period begins with Terminal 5 and 6 being energized simultaneously. This
is known as PTFI (Pilot Trial for Ignition). The ED510 will display:
PTFI
00:02
IGNITION TIMING
This period is ten seconds in duration. If no flame is detected after ten seconds, the control will de-
energize Terminals 5 and 6 and lockout. When flame is detected during this 10 second period, the
ED510 will display
PTFI 20
FLAME SIGNAL
9.
With flame proven at the end of PTFI, the main flame trial for ignition (MTFI) period begins.
Terminal 7 is energized. The ED510 will display:
MTFI 35
FLAME SIGNAL
Terminal 5 is de-energized 10 seconds later and Terminal 6 is de-energized after another 5 seconds.
10.
The firing rate motor is now sent to the auto position (10-11 circuit made) and is under the com-
mand of the proportional controller. The ED510 will display:
AUTO 40
FLAME SIGNAL
NOTE: Trial-for-Ignition timings depend on the programmer selected. The timing charts in the
beginning of this bulletin point out the differences in the various programmers.
2SVQEP7LYXHS[R
1.
When the operating control circuit (L1-13) opens, the main fuel valve is de-energized. The firing
rate motor is driven to the low purge position (10-12 circuit made).
2.
Following a 15 second post purge, the burner/blower motor is de-energized.
3.
The burner is now off and the ED510 will display
STANDBY
L1-13 OPEN
Burner history can be displayed by using ED510 keypad. See bulletin ED-5101.
*
Prepurge timing is selectable via dipswitches.
FLAME SIGNAL
2361%0
1-2-191%'')48%&0)
238%'')48%&0)
