AERCO KC Series Equipped with C-More Controller for Massachusetts Only - Manual (Page 18)

INSTALLATION
2-8
INTL’K IN. Both interlocks, described below, are
factory wired in the closed position.
NOTE:
Both the Delayed Interlock and Remote
Interlock must be in the closed position to
allow the unit to fire.
2.6.10.1 REMOTE INTERLOCK IN
The remote interlock circuit (REMOTE INTL’K
IN) is provided to remotely start (enable) and
stop (disable) the unit if desired. The circuit is
24 VAC and comes factory pre-wired closed
(jumped).
2.6.10.2 DELAYED INTERLOCK
The delayed interlock circuit (DELAYED INTL’K
IN) is typically used in conjunction with the
auxiliary relay described in paragraph 2.6.11.
This interlock circuit is located in the purge
section of the start string. It can be connected to
the proving device (end switch, flow switch etc.)
of an auxiliary piece of equipment started by the
unit’s auxiliary relay. The delayed interlock must
be closed for the heater to fire. If the delayed
interlock is connected to a proving device that
requires time to close (make), a time delay (Aux
Start On Dly) that holds the start sequence of the
unit long enough for a proving switch to make
(close) can be programmed. Should the proving
switch not prove within the programmed time
frame, the unit will shut down. The Aux Start On
Dly can be programmed from 0 to 120 seconds.
This option is locate in the Configuration Menu
(Section 3).
2.6.11 FAULT RELAY
The fault relay is a single pole double throw
(SPDT) relay having a normally open and
normally closed set of relay contacts that are
rated for 5 amps at 120 VAC and 5 amps at 30
VDC. The relay energizes when any fault
condition occurs and remains energized until the
fault is cleared and the CLEAR button is
depressed. The fault relay connections are
shown in Figure 2.10.
2.6.12 AUXILIARY RELAY CONTACTS
Each unit is equipped with a single pole double
throw (SPDT) relay that is energized when there
is a demand for heat and de-energized after the
demand for heat is satisfied. The relay is
provided for the control of auxiliary equipment,
such as pumps and louvers, or can be used as a
unit status indictor (firing or not firing). Its
contacts are rated for 120 VAC @ 5 amps.
Refer to Figure 2.10 to locate the AUX RELAY
terminals for wiring connections.
mA OUT
RS-485
COMM.
+
-
+
-
ANALOG IN
SENSOR COMMON
OUTDOOR SENSOR IN
REMOTE INTL'K IN
B.M.S. (PWM) IN
SHIELD
+
-
+
-
AUX SENSOR IN
NOT USED
EXHAUST SWITCH IN
DELAYED INTL'K IN
FAULT RELAY
120 VAC, 5A, RES
AUX RELAY
120 VAC, 5A, RES
G
RELAY CONTACTS:
120 VAC, 30 VDC
5 AMPS RESISTIVE
DANGER
120 VAC USED
IN THIS BOX
NOT USED NOT USED
NC
COM
NO
NC
COM
NO
NOT USED
Figure 2.10 I/O Box Wiring