Specifications

6
CONTROL WIRING
1. Use min. 600 volts, NEC Class 1 insulated wire for all control
circuit wiring.
2. Use a crimp-on type fork terminal on the wire ends that attach
to the control terminal board if more than one connection is
to be made under the terminal screw.
3. On units not provided with internal contactor
(3 & 5 KW), refer
to Figure 4 for wiring diagram.
Note: Thermostat and control circuit wiring must be suitable
to handle the full load of the heater (example HUHAA520 is
rated 24 amps)
4. On units provided with internal contactor
(units rated 7 KW
and higher) refer to Figure 5 for wiring diagram. Control
wiring must be rated minimum 18 AWG.
LINE VOLTAGE IS PRESENT ON SOME OF THE TERMI-
NALS ON THE CONTROL TERMINAL BOARD. ALWAYS
DISCONNECT THE POWER FROM THE HEATER BEFORE
MAKING ANY CONNECTIONS TO THE CONTROL BOARD
TO PREVENT ELECTRIC SHOCK HAZARD.
MT-1
MT-2
2-STAGE
INTERNAL
THERMOSTAT
BLACK
RED
RED
BLACK
P2
H2
F 1
F 2
S
REMOTE SUMMER
FAN SWITCH (MRFS-1)
OR SUMMER FAN
SWITCH MCFS (MANUAL)
P1
H1
REMOTE SUMMER FAN
SWITCH (HUHAARFS-1) OR
SUMMER FAN SWITCH
HUHAAFS (MANUAL)
HUHAA MT-2
HUHAA MT-1
Figure 4. Control Terminal Board
(for Heaters Without Contactors)
Mounting
Basic Model Height Width Depth Weight
No. in (mm) in. (mm) in. (mm) lbs. (kg)
!
Table 4. Specifications
HUHAA320
HUHAA324
HUHAA327
HUHAA348
HUHAA520
HUHAA524
HUHAA527
HUHAA548
HUHAA720
HUHAA724
HUHAA727
HUHAA748
HUHAA1020
HUHAA1024
HUHAA1027
HUHAA1048
HUHAA1520
HUHAA1524
HUHAA1548
HUHAA2020
HUHAA2024
HUHAA2048
HUHAA2524
HUHAA2548
HUHAA3020
HUHAA3024
HUHAA3048
HUHAA4024
HUHAA4048
HUHAA5020
HUHAA5024
HUHAA5048
16
(406.4)
21-3/4
(552.5)
21-3/4
(552.5)
30
(76.2)
30
(76.2)
14
(355.6)
19
(482.6)
19
(482.6)
26-5/8
(676.4)
26-5/8
(676.4)
8-1/2
(214.4)
8-1/2
(214.4)
13-3/4
(346.8)
13-3/4
(346.8)
18-1/8
(457.2)
27 (12.2)
27 (12.2)
27 (12.2)
27 (12.2)
27 (12.2)
27 (12.2)
27 (12.2)
30 (13,6)
38 (17.2)
38 (17.2)
38 (17.2)
38 (17.2)
38 (17.2)
38 (17.2)
38 (17.2)
38 (17.2)
53 (24.0)
53 (24.0)
53 (24.0)
60 (27.2)
60 (27.2)
60 (27.2)
93 (42.3)
93 (42.3)
93 (42.3)
93 (42.3)
93 (42.3)
119 (54.0)
119 (54.0)
119 (54.0)
119 (54.0)
119 (54.0)
WARNING
NOTES:
1. THIS STYLE CONTROL TERMINAL BOARD
USED WITH MODELS HUHAA320,
HUHAA324, HUHAA327, HUHAA520,
HUHAA524, HUHAA527.
2. WHEN UNIT IS WIRED FOR SINGLE PHASE,
JUMPER H1 TO H2. IF SINGLE POLE
THERMOSTAT IS USED WITH SINGLE PHASE
UNIT, CONNECT THERMOSTAT LEADS TO
P1 AND H1.
3. EXTERNAL LINE VOLTAGE THERMOSTATS
SHOULD BE TREATED AS SINGLE STAGE
ONLY.