Model 702G/O Advanced gas/oil burners — Instruction manual
Carlin part number MN702GO Rev. 06/23/14
– 19 –
Where appliance instructions differ from this manual, follow the appliance instructions.
Figure 15a
702G/O Mass Code ladder wiring
diagram (burners with RM7895C or
RM7897C primary only); see Figure 12
for a legend to callouts
Figure 14a
702G/O field wiring connections
(RM7895C or RM7897C
only)
Low-High-Low step modulation
1. To take advantage of the energy-saving potential of the Model 702G/O
combination gas/oil burner, it should be wired to operate at low-high-low
cycles. The firing cycle can be much longer using low-high-low firing,
because the burner can cycle to low fire as demand decreases. This keeps
the burner on longer, reducing cyclic losses.
2. The appliance must be equipped with a high fire control. This would be a
make-on-fall control, either temperature (water boiler) or pressure (steam
boiler) activated. Read the appliance manual for the location of the high
fire control, when used.
3. See Figures 14a and 15a to connect the high fire control to the burner
firing rate circuit.
4. The burner includes a pre-wired manual high-fire switch. Close this switch
to hold the burner in high fire mode. Open the switch to hold the burner
in low fire mode.
5. Wire the burner — RM7895C/RM7897C primary control
(continued)
