MPO-IQ Installation, Operating, and Service Instructions

49
Figure 31A: R7184 Oil Primary Terminals,
LED and Reset Button
IX. SYSTEM START-UP (continued)
WARNING
Before installation of the boiler is considered
complete, the operation of all boiler controls must
be checked, particularly the primary control and
high limit control.
J. VERIFY HONEYWELL OIL PRIMARY FEATURES
using procedures outlined in Instructions furnished with
control or instructions as follows:
1. R7184 / R7284 FEATURES AND CONTROLS
a. The Oil Primary is a microprocessor-based control.
The indicator light provides diagnostic information
for lockout, recycling and patented cad cell status.
There is a manual reset button to exit the Lockout
Mode and enter the Idle Mode (see Figure 31A).
b. Pump Priming Cycle: To facilitate purging air from
the oil lines and lters, the R7184 can be placed in
a purge routine by pressing and releasing the reset
button during the safety check, delayed valve-on,
ignition or carry-over periods.
The R7284 can be placed in a purge routine by
pressing and releasing the up arrow button during
the Trial For Ignition. “Pump Prime” is shown
on the oil primary display along with the time left
on the Trail for Ignition (TFI). Pressing the up
arrow button adds a minute to the TFI time for a
maximum of 10 additional minutes. (press the up
arrow button 10 times). Pressing the down arrow
subtracts a minute from the TFI time (see Figure
31B).
c. Limited Recycle: This feature limits the number of
recycle trials (for each call for heat) to a maximum
of three trials. If the ame is lost three times and
does not successfully satisfy a call for heat, the Oil
Primary locks out.
d. Limited Reset (Restricted Mode): In order to limit
the accumulation of unburned oil in the combustion
area, the control can only be reset three times. The
reset count returns to zero each time a call for heat
is successfully completed.
e. T-T Jumper: All R7184 models have pre-installed T-T
jumper. Do not remove jumper. (See Figure 31A).
All R7284 models have internal "TT Congured ON"
parameters set to "ON".
f. R7184 Diagnostic LED: The indicator light on oil
primary control provides lockout, recycle and cad
cell indications as follows:
• Flashing at 1 Hz (½ second on, ½ second
off): system is locked out or in Restricted
Mode.
• Flashing at ¼ Hz (2 seconds on, 2 seconds
off): control is in Recycle Mode.
• On: cad cell is sensing ame.
• Off: cad cell is not sensing ame.
The R7284 has an LCD display and simply displays
lockout and ame status on it.
g. Cad Cell Resistance Check: For proper operation
it is important that the cad cell resistance is below
1600 ohms.
Cad Cell Resistance (ohms) is measured by the oil
primary. The thresholds are:
< 1600 Ohms Normal operation
> 1600 Ohms Service burner soon
> 6100 Ohms Flame loss, burner shuts down
> 9999 Ohms Check for broken cell or wire.
During a normal call for heat, once the R7184
control has entered the Run Mode, press and release
the reset button. Indicator light will ash 1 to 4
ashes. See Table 9 for equivalent cad cell
resistance.
R7284 displays resistance in ohms during Running
Mode.
TABLE 9: R7184 CAD CELL RESISTANCE WHEN
SENSING FLAME
Flashes Cad Cell Resistance in ohms
1 Less than 400
2 More than 400 and less than 800
3 More than 800 and less than 1600
4 More than 1600 and less than 5000
Figure 31B: R7284 Oil Primary Terminals,
Display and Function Buttons