Proportional (Ssr) Electric Heat Start-Up, Operation And Service; Start-Up; Input Setting - Carrier 35E Installation And Start-Up Instructions Manual

PROPORTIONAL (SSR) ELECTRIC HEAT
START-UP, OPERATION AND SERVICE
Proportional SSR Heat is an electronic, time-proportional
electric heat system. The heat output of the heater is modulat-
ed utilizing quiet, rapid performing solid state relays. The re-
lays are switched off and on to allow the heating of electrical
resistance elements. The proportion of time the relay is on
dictates the proportion of maximum heat the electric heater
can produce. The solid state relays are switched off and on by
a supplied Electric Heat Module (EHM). The EHM accepts
an input signal from the terminal unit controller or thermostat
for the amount of heat desired. The EHM can accept a variety
of different input signals when interfacing with controls. The
type of input the EHM will accept is modified by changing
the position of one or two jumpers easily accessible on the
board.
Proportional SSR Heat is available with an optional discharge
temperature sensor. When used with the discharge sensor op-
tion, the Proportional SSR Heat system will modulate outgo-
ing temperature from the unit between the maximum tem-
perature setting and initial temperature of incoming air before
heating began. The discharge temperature setpoint is easily
adjusted in the field by rotating the temperature dial on the
APPLICATION
LX1 — On/Off
LX2 — 2 Stage (2Stg)
LX3 — 0-10V
LX4 — 2-10V
LX5 — Incremental (Incr)
LX6 — Binary (Bin)
LX7 — 3 Point Floating (Float)
Table 9 — Proportional SSR Heat Applications
DESCRIPTION
This application accepts one 24 vac input at "Inc" to step the heater output
from OFF to 100% heater kW rating. The signal may be pulsed off and on
over a small time period to provide proportional heat. For example, a signal
that is on for 4.5 seconds every 10 seconds would produce 45% of the
heater's kW rating.
This two stage application accepts two 24 vac inputs to step the heater out-
put from off to 50% or 100% heater kW rating. A signal to "Inc" is 50% and a
signal to "Dec" is 100%
This application accepts a 0-10 vdc (0-20mA) signal to modulate the heater
output. The output is proportional to input signal (for example, 4.5 volts sets
the heater to 45% of kW rating).
This application accepts a 2-10 vdc (4-20 mA) signal to modulate the heater
output. The output is proportional to input voltage above 2 volts (for example,
4.5 volts sets the heater to 25% of kW rating).
This application accepts one 24 vac input to modulate heater output. An
increase signal will increase the heater output from 0% to 100% over a 4-
minute 15-second interval, staying at 100% afterward. When the signal is
removed, the heater output will decrease to 0% over the same time period.
This application mirrors a Normally Closed hot water valve.
This application accepts two 24 vac inputs to step the heater from off to 33%,
67%, or 100% of the heater's kW rating. A signal to "Inc" is 33%, a signal to
"Dec" is 67%, and a signal to both is 100%.
This floating input application accepts two 24 vac inputs to increase or
decrease the heater output. As the increase signal is sent, the heater output
will increase from 0% to 100% over a 4-minute 15-second interval. If the
increase signal is removed, or a decrease signal is also added, the heater
output will stay constant at present point. When only the decrease signal is
received, the heater output will decline from the present level to 0% over the
same time period. This application mirrors a three-point floating hot water
valve.
EHM. The EHM will not allow temperatures over the set-
point so as to prevent overheating, stratification, and energy
waste from heated air lost through overhead returns.
Units with Proportional SSR Heat use solid state relays,
which generate heat when used. The temperature of the
control box and/or heat sinks may be hot to the touch,
causing personal injury.

Start-Up

INPUT SETTING

The Proportional SSR Heat board can be controlled and oper-
ated in 7 different ways. The units are ordered with an LXY
code, where X is coded for unit power and Y is coded for the
application (1-7). This Y application can be changed in the
field. The application desired is chosen by placement of
jumpers in the corner of board (see Fig. 15). The jumper set-
tings shown in Table 9 represent the pins at the bottom corner
of the control board as shown in Fig. 15. See Fig. 16-22 for
application wiring diagrams.
17
WARNING
JUMPER SETTINGS