6
F100d
JAN 2011
FROST MASTER
®
PLUS DEFROST CONTROLLER
TERMINATE (
Plus
MODELS)
The defrost terminate feature is built-in to the Frost
Master®
Plus
models. It consists of an accurate,
dur a ble temper atur e sensor a nd a ter minate
temperature setting adjustment on the face of the
defrost controller. When the terminate temperature
is satisfied, the HOT GAS step (or even the SOFT GAS
step) will cease and the EQUALIZE step will begin.
By ending the HOT GAS step as soon as the coil is
clean, a quick and efficient defrost occurs. If the
terminate temperature feature is not desired, simply
do not connect the temperature sensor and the HOT
GAS step will operate on time only.
The terminate temperature adjustment setting range
is from 30ºF to 65ºF (-1°C to +18°C); and is usually
set about 40ºF (4°C). If the terminate temperature is
not reached, the hot gas supply or other frost melting
medium will be terminated by the HOT GAS step time
duration. Coincidentally, be sure that the HOT GAS
step setting duration is long enough to always permit
a complete defrost. If unsure, set time duration to
maximum.
Locate the terminate temperature sensor at the last
place of the evaporator coil where frost or ice remains
during a defrost. Fasten sensor to evaporator or
piping. Join each of two 6 ft. (183 cm) long sensor
wire leads to field sensor wires using the supplied
watertight solderless joint connectors. Carefully
crimp then heat to seal joint from moisture. Field
sensor wire size should be at least 20 AWG (0.5 mm2)
and limited to a distance of 500 ft. (152 m). Avoid
running wires through evaporator air stream or with
high voltage wiring. Connect field sensor wires to
terminate temperature sensor quick disconnect plug
inside defrost controller enclosure.
TERMINATE TEMPERATURE SENSOR
INTRODUCTION
This deluxe model, Frost Master® Plus, includes an
additional (fifth) defrost step, SOFT GAS, plus a built-
in, adjustable, Temperature Terminate feature with
clamp-on “defrosted” sensor. Also, the PUMPOUT
and EQUALIZE defrost step times are greater than
the standard Frost Master®; otherwise, operation
is the same.
The SOFT GAS step permits the gradual build-up of
pressure inside the evaporator. This is accomplished
by opening a small soft (hot) gas solenoid valve prior
to opening a primary hot gas solenoid valve during the
HOT GAS step. This primes the evaporator for hot gas
full flow. The soft gas solenoid valve will remain open
throughout the SOFT GAS and HOT GAS steps.
The built-in Temperature Terminate feature enables
operator to easily adjust the terminate temperature
setting without having to climb a ladder to reach the
thermostat (temperature switch) on an evaporator.
TYPICAL APPLICATION
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TERMINATE TEMPERATURE
SETTING ADJUSTMENT
TERMINATE TEMPERATURE
SENSOR QUICK
DISCONNECT PLUG
RELAY SG (SOFT GAS)
TERMINALS
DEFROST STEPS
TIME ADJUSTMENTS
PUMPOUT: 0 TO 45 MIN
SOFT GAS: 0 TO 5 MIN
HOT GAS: 0 TO 45 MIN
EQUALIZE: 0 TO 10 MIN
FAN DELAY: 0 TO 5 MIN
0.50''
1.25''
0.25''
SIDE VIEW
TOP VIEW
(6 mm)
(32 mm)
(13 mm)
0.50''
1.25''
0.25''
SIDE VIEW
TOP VIEW
(6 mm)
(32 mm)
(13 mm)
