Electric Defrost - Hussmann IMPACT RLN Technical Data Sheet

Fan and Heater Circuits - Electric Defrost (standard)
208V
1
R
2
R
3
R
120V P
OWER
14 COM
B
16
B
13
B
120V POWER
Switch
17
OR
Defrost Termination
FIELD WIRED
Thermostat
DB
Low Temperature with

Electric Defrost

R R R
1 2
Permanent Internal
Jumpers
DEFROST HEATERS
(208V)
Electric Defrost Sequence – Low Temperature
1. Power from the defrost contactor energizes Defrost Heaters and 208V Evaporator Fan Relay Coil (7). Relay Contacts open the fan
circuit and energizes the Drain Pan Heater.
2. If the Defrost Heater raises internal air temperature above 90°F, the Defrost Limit Thermostat (4) will open.
3. Temperature rise of the evaporator closes the Relay Control Thermostat (5) at about 35°F, energizing 120V A.S. Relay Coil (6). This
relay's contacts open the Frame and Door Heater Circuits.
4. When Defrost Termination Thermostat ends defrost period, the defrost contactor opens the Defrost Heater and Evaporator Fan Relay
Coil Circuits. The Drain Pan Heater goes off and fans are on.
5. Temperature fall of the evaporator opens the Relay Control Thermostat (5) at about 20°F, de-energizing 120V A.S. Relay Coil (6).
A.S. Relay Contacts close the Frame and Door Heater Circuits.
P/N 0435490_G
Low Temperature
CIRCLED NUMBERS = PARTS LIST ITEM NUMBERS
R = Red P = Purple 2P = Purple (2 Bands) DB = Dark Blue B = Black
BR =Brown Y =Yellow OR = Orange W = White
THESE ARE MARKER COLORS (WIRE MAY VARY.)
Evaporator Fan
Rear Defrost Heater 8
Front Defrost Heater
8
Fan Relay
7
F
N.C.
Fan Relay
7
F
N.O.
Y
Relay Control
C.O.R.
6
A.S. Relay
A.S.
COM
N.C.
10
B
N
EUTRAL
11
12
20
L
OR
2
DB
C.O.R.
Terminal Blocks in Raceway
R B B R R B P 2P
3 4 5 6 7 8 10 11 12
Removable External
FANS & A.S.
Jumpers
(120V)
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A. • WWW.HUSSMANN.COM
7
Relay Coil
1
3
C
R
8
R
7
R
4
Defrost Limit
6
B
O.O.R.
N.C.
1
Evaporator Fans
BR
Rod Heater (Drain) 9
Y
6
A.S. Relay
5
Coil
3 1
c
W
Frame A.S. Heaters
P
Door A.S. Heaters
2P
B B B OR OR 2P P W
13 14 16 17 20 21 22 24
LIGHTS
LIGHTS
(120V)
(Neutral)
208V
CAUTION: When multiplexing
4
merchandisers equipped with defrost
heaters, if branch circuit overcurrent
protection is larger than the
individual merchandiser's defrost
circuit load, then additional
supplemental overcurrent protection
may be required per NEC Articles
210 and 240.
5
B
N
EUTRAL
26
Refer to Innovator Reach-In
Glass Door, Installation and
Service manual, P/N 0425683,
25
for Innovator door and frame
replacement parts.
24
22
P
Defrost Termination
21
2P
Thermostat
Refrigeration
Thermostat
(Optional)
Pink
Y BR
Dark Blue
25 26
FANS & A.S. (Neutral)
2
3
} To
Condensing
Unit
5 of 6