Wiring - Carrier 35E Installation And Start-Up Instructions Manual

WIRING

See Fig. 15. The EHM control board is powered by 24vac
(Fig. 15, item 1) from the transformer in the electric heater.
The EHM has auxiliary 24vac outputs (Fig. 15, item 2) that
can be used to power the unit's electrical controls. Next to the
"Xfmr" inputs are the "+" and "–" relay connections (Fig. 15,
item 3) that control the solid state relays by sending pulses of
~25vdc.
There are two terminations to use for dc volt control (Fig. 15,
item 4) of the electric heat (applications LX3 and LX4).
These are polar sensitive. The "+" signal from the controller
must be connected to "Signal" on the EHM Control Board.
The "–" from the controller must be connected to "Com" next
to "Signal" (not "iCom"). A termination to "–" is possible,
but not necessary, to measure mA signals to the board.
7
2 4 6
1
3
Fig. 15 — EHM Control Board
YELLOW #18
LX1
BLUE #18
ON/OFF
HEATER
APPLICATION
Com
Tcal
24Vac Neutral
Xfmr
24Vac Neutral
YEL #18
BLUE #18
TO HI
VOLTAGE
RED #18
ENCLOSURE
BLACK #18
Fig. 16 — LX1 Application Wiring
There are three terminations for 24vac control (Fig. 15, item
5) of the electric heat (applications LX1, LX2, LX5, LX6,
and LX7). "Inc" is for the increase signal in applications LX5
and LX7, as well as the first stage heat signal in applications
LX1, LX2, and LX6. "Dec" is for the decrease signal in ap-
plication LX7, as well as the second stage heat signal in ap-
plications LX2 and LX6. A connection to "iCom" is neces-
sary for all of these 24 vac applications. If the unit's control-
ler does not have a common output, a jumper to the correct
"Aux" terminal can be used. If the unit controller outputs the
"24vac" side from its input power, a jumper should be made
from "Neutral" to "iCom" (see sample schematic, Fig. 23). If
the unit controller outputs the "Neutral" side of its input pow-
er, a jumper should be made from "24vac" to "iCom".
5
JUMPER
SETTING
TO
CONTROLS
POWER
Red
Black
CONTROLS
BLACK #18
COMMON
RED #18
CONTROLS
HEATER
OUTPUT
49°C
120°F
32°C
90°F
20°C
EVO/EHM-
68°F
0-10V
2-10V
+ Relay -
Float
2Stg
Incr
SSRs
Select Sequence>
On/Off
Bin
+ Relay -
PLACE
JUMPERS
ON PINS
DESIGNATED
FOR CONTROL
SEQUENCE
18
DISCHARGE
TEMPERATURE
SETTING
DIAL
OPTIONAL
DISCHARGE
TEMP
SENSOR