FULTON PHW 1000, Installation, Operation And Maintenance Manual

Page: 69 / 94

Fulton Heating Solutions, Inc. -- PHW Manual -- 2010-0713
Page 69
4. At Low Fire the linkage arms should NOT begin or finish travel in the vertical
position. If this occurs there is a possibility that the gears will bind and cause
damage to the mod motor.
h) Procedure to Zero and Span the Modulation Motor
1. The following procedure is done on each modulation (mod) motor at the factory.
It may be necessary to do in the field in the event the mod motor requires
replacement or the mod motor linkage is moving up or down the range when
there is no change in the operating or setpoint temperature difference.
a) Turn boiler OFF.
b) Put the temperature control in manual mode (press the A/M key once –
the SP display will show a value between 0 and 100).
c) Follow the electrical drawing and remove the connection between (F)
and (-) on the mod motor. Disconnect relay CR3 for safety.
d) Contact point 16(+) on the temperature control is wired through CR1
normally closed to contact point (+) on the mod motor. Contact point 17(-
) on the temperature control must be disconnected. Install a jumper from
17(-) to contact point (-) on the mod motor. This will provide a direct
connection between (+) and (-) on the temperature control to (+) and (-)
on the mod motor.
e) Refer to the zero and span adjustment information for the mod motor
(Pages 5 and 10). Follow steps 1 through 8 on page 10 of the mod
motor brochure included in the Pulse Operation and Maintenance
manual.
f) Be sure the linkage does not bend or catch in any position during travel.
g) When zero and span are complete, scroll the input rate to 100% - this will
drive the burner to high fire and purge any left over combustibles- and
adjust the blue cam, if necessary, until the high edge of the cam pushes
against the end switch.
h) Remove the jumper and install the wire on contact point 17(+) of the
temperature control. Connect relay CR3.
i) Test the mod motor signal by manually setting the output signal from
zero (low fire – 4 mA) to 100 (high fire – 20 mA). At high fire, the slot in
the shaft of the mod motor should be horizontal in orientation.
Note
The unit will still shut off at setpoint plus 5°F (standard settings). Also, being in
manual mode, the temperature control ignores any PID or auto tune settings.