AERCO KC1000 Heater 2002 - Manual (Page 14)

INSTALLATION
2-6
2.5.1 ELECTRICAL REQUIREMENTS
Electrical requirements for each unit are 120
VAC, 1 Phase, 60 Hz, 20 Amps from a dedicated
electrical circuit. No other devices should be on
the same electrical circuit as a KC1000 unit. A
means for disconnecting AC power from the unit
(such as a service switch) must be installed near
the unit for normal operation and maintenance.
All electrical connections should be made in
accordance with the National Electrical Code
and/or with any applicable local codes.
The electrical wiring diagram is shown in Figure
2.8. Conduit should be run from the knockouts in
the side of the box in such a manner that it does
not interfere with the removal of any sheet metal
covers. A flexible electrical connection may be
utilized to allow the covers to be easily removed.
USE COPPER CONDUCTORS ONLY FOR FIELD WIRING
60 HZ
DISCONNECT POWER BEFORE SERVICING
DANGER: HIGH VOLTAGE
20 AMP
120 VAC,
NEUTRAL
GROUND
LINE
POWER BOX
AERCO INTERNATIONAL INC.
INPUT POWER
Figure 2.8
AC Power Wiring Diagram
2.6 FIELD CONTROL WIRING
Each unit is fully wired from the factory with an
internal operating control system. No field control
wiring is required for normal operation. However,
the KC1000 control system does allow for some
control and monitoring features. Wiring for these
features can be accomplished in the I/O Box
behind the left side panel (Figures 2.9 and 2.10).
The I/O Box is common to both KC1000 water
heaters and boilers. While some of the inputs
and outputs are common to both water heaters
and boilers, some are not applicable to both.
These are noted in the following paragraphs.
CAUTION!
DO NOT make any connections to the I/O
Box terminals labeled “NOT USED”.
Attempting to do so may cause equipment
damage.
GAS SHUT-OFF
VALVE
I/O BOX
BLOWER
Figure 2.9
Input/Output (I/O) Box Location
2.6.1 OUTDOOR AIR SENSOR IN
Not applicable to Water Heaters.
2.6.2 AUX SENSOR IN
The AUX SENSOR IN terminals can be used to
add an additional temperature sensor for
monitoring purposes. This input is always
enabled and is a view only input that can be
seen in the operating menu. The sensor must be
wired to the AUX SENSOR IN and SENSOR
COMMON and must be similar to AERCO
BALCO wire sensor P/N 12449. A resistance
chart for this sensor can be found in Appendix C.
2.6.3 ANALOG IN
The ANALOG IN + and – terminals are used
when an external signal is used to change the
setpoint of the water heater when operating in
the Remote Setpoint Mode.
Either a 4 to 20 mA / 1 to 5 VDC or a 0 to 20 mA/
0 to 5 VDC signal may be used to vary the
setpoint or firing rate. The factory default setting
is for 4 to 20 mA / 1 to 5 VDC, however this may
be changed to 0 to 20 mA / 0 to 5 VDC using the
Configuration Menu described in Section 3. If
voltage rather than current is selected as the
drive signal, a DIP switch must be set on the
CPU Board located inside the Control Box.
Contact the AERCO factory for information on
setting DIP switches.
All supplied signals must be floating (un-
grounded) signals. Connections between the
source and the Heater’s I/O Box must be made
using twisted shielded pair wire of 18 –22 AWG,
such as Belden 9841(see Fig. 2.10). Polarity
must be maintained and the shield must be