Hussmann ISCGG-D, Installation And Service Instructions Manual

Page: 13 / 33

Page 13
CONTROLS & ADJUSTMENTS – MIXED MULTIPLEXING
Refrigeration temperature may be controlled by a refrigeration thermostat sensing discharge air
temperature. The thermostat controls a liquid line solenoid (optional) or a suction line solenoid
(optional).
Electric defrost is time initiated and temperature terminated. Termination is initiated by a
“close-on-rise” Klixon sensor mounted on an evaporator tube.
“Off-time” defrost is time initiated and time terminated.
REFRIGERATION CONTROLS
DEFROST CONTROLS
e
Length of Defrost
MODEL
A
P
P
L
IC
A
T
IO
N
DISCHA
RG
E
AIR TEMP
c
D
E
F
R
O
S
T
F
re
qu
en
cy
(Hours)
E
le
ct
ri
c
(M
inutes
)
O
F
F
TIME
K
O
O
L
GAS
Low Temp
(Frozen Food)
- 10
°
F
30 - 16
ISFGG-R
Medium Temp
(Dairy, Deli)
+ 24
°
F
30 - 16
ISMGG-
R
Medium Temp
(Dairy, Deli)
+ 24
°
F
E
ve
ry
12 Hours
- 70 12
c
Discharge air temperature is to be measured by attaching a service thermometer to the discharge
honeycomb at the centre of the case. Adjust the refrigeration control to maintain the discharge
air temperature shown above.
e
If these spot display refrigerators are to be multiplexed with a different type refrigerator,
compare these defrost settings with those specified for the other refrigerator. If these settings are
not compatible, refer to the previous page.
f
KOOLGAS defrost is time initiated and time terminated. The defrost lengths listed above are
based upon laboratory testing but operation under actual store conditions may require that they
be lengthened to accomplish a thorough defrost. Some of the store conditions that can contribute
to a longer defrost are: low head pressure, long runs of refrigerant lines, store ambient, fixture
temperature operating lower than that recommended, seasonal ambient changes etc.
Each system shown on the “store legend” must have staggered defrosts to maintain stable compressor
loading and a sufficient supply of defrost gas.