AERCO KC1000 Heater Mar 2011 - Manual (Page 16)

INSTALLATION
2-8
2.6.9.1 REMOTE INTERLOCK IN
The remote interlock circuit is provided to
remotely start (enable) and stop (disable) the
unit if desired. The circuit is labeled REMOTE
INTL’K IN and is located inside the I/O Box on
the left side of the unit. The circuit is 24 VAC
and comes factory pre-wired closed (jumped).
2.6.9.2 DELAYED INTERLOCK
The delayed interlock 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 equip-
ment 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).
2.6.10 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 2.11.
2.6.11 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 2.11 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 2.11 I/O Box Wiring