Rev 8/2014
PrecisionTemp, Inc • 11 Sunnybrook Drive • Cincinnati, Ohio, 45237 • 1-800-934-9690 •
fax 513-641-0733 21
PT-200RC (Recirculating)
Design and Sequence of Operation
The PT-200RC gas booster heater is designed for use when a PT-200FT (Flow through)
cannot be used. It is for use when the booster must be remotely located from the
dishmachine. The National Sanitation Foundation requires any booster that is not
located within 5 feet of the dishmachine must have a recirculation system installed. The
PT-200RC system includes the booster heater, circulation pump, expansion tank, and
holding tank.
The PT-200RC is an on-demand water heater. During operation, any time the T-mid
thermister senses the water temperature drop below the factory set temperature, the
burner ignites and heats the dish machine rinse water. This water is circulated by the
pump through a recirculation line from the outlet of the booster, to the recirculation tank
mounted near the dishmachine, then back to the booster. This provides constant hot
water in the line and prevents temperature loss.
The sequence of operation is as follows:
•
Power is on and the power switch glows and green LED flashes. The pump is circulating
water from the booster to the tank and on to the dish machine and back to the booster.
Note: The next steps take place in 3-5 seconds.
•
The T-mid thermister on the booster sense low water temperature and sends a flow
signal to the control board.
•
The green control board sends 12v DC through the brown wire to the pressure differential
switch and on to the black solid-state relay that powers the power vent blower.
•
The relay closes the 110v AC contacts to start the blower.
•
Fluing is proofed by the clear vacuum tube that runs from the blower to the pressure
differential switch.
•
The pressure differential switch contacts close, sending 12v DC to the black spark
ignition module via the grey wire.
•
The ignition module simultaneously effects a spark through the high limit switch through
the heavy yellow wire to the spark ignition probe over the burner and sends 12v DC to the
combination gas valve via the blue wire. Two ignition attempts last up to a maximum of
5.5 seconds. The digital temperature read-out displays (if installed, otherwise, check
temperature on spring gauges).
•
Ignition of the burner’s center element is effected and the flame is proofed and monitored
through the same yellow wire by the spark ignition module.
•
The micro-processor on the control board monitors water temperature with the T-mid
thermisters twice per second and varies voltage 0 – 22v DC to the gas modulating valve,
varying gas flow to burner in order to maintain constant temperature output.
•
Burner will modulate down as tank temperature approaches set temperature.
•
Burner remains lit as long as the water in the tank is below set temperature, but if flame is
extinguished for any reason, the gas valve will shut off in less than
1 second and re-ignition will be attempted.
