IOM-T-294EXP
2214
© 2022 tekmar
7
Modulating Boilers (Terminals 4 to 11)
The control provides either a 0-10 V (dc) or a 4-20 mA output to each boiler . Polarity is important .
• Connect the control Mod (+) terminals 4, 6, 8, 10 to boilers 5, 6, 7 and 8 analog signal input (+)
respectively .
• Connect the control Mod (-) terminals 5, 7, 9, 11 to boilers 5, 6, 7 and 8 analog signal input (-)
respectively .
Some modulating boilers may also require a boiler on/off enable signal in addition to the
modulating signal. Please consult the boiler manual.
Modutrol IV
tekmar
B
R
W
+
-
tekmar
V9055
+
-
B
R
W
Modutrol IV™
0 - 135
Ω
Actuating
Motor
B
R
W
Mod
+
-
Modutrol IV
tekmar
B
R
W
+
-
tekmar
V9055
+
-
B
R
W
B
R
W
V9055™
0 - 135
Ω
Actuating
Motor
Mod
+
-
The 4 to 20 mA output can be converted to a 0 - 135 Ω
output for a Modutrol IV™ gas valve actuating motor using a
0 - 135 Ω tekmar Converter 005 (sold separately) .
The 4 to 20 mA output can be converted to a 0 - 135 Ω
output for a V9055™ gas valve actuating motor using a
0 - 135 Ω tekmar Converter 005 (sold separately) .
Boiler
Control
294
Boiler
Control
294
Modutrol IV™ and V9055™ are trademarks of Honeywell, Inc .
Boiler Enable (Terminals 12 to 19)
A single stage condensing or non-condensing boiler is enabled through the TT contacts .
• For Boiler 5 connect the Boiler Enable terminals 12 and 13 to the boiler TT contacts .
• For Boiler 6 connect the Boiler Enable terminals 14 and 15 to the boiler TT contacts .
• For Boiler 7 connect the Boiler Enable terminals 16 and 17 to the boiler TT contacts .
• For Boiler 8 connect the Boiler Enable terminals 18 and 19 to the boiler TT contacts .
Boiler Expansion (Terminals 1, 2, 3)
The control operates 4 on board boilers and is expandable in groups of 4 up to a
maximum of 16 through the use of boiler expansions . The control connects to the
expansion through a wired three-wire connection . The maximum bus cable length is
100 feet (30 m) using 18 AWG solid conductor cable .
• Connect the 294 terminal 18 (-) to the 294EXP terminal 1 (-) .
• Connect the 294 terminal 19 (+) to the 294EXP terminal 2 (+) .
• Connect the 294 terminal 20 (Gnd) to the 294EXP terminal 3 (Gnd) .
18 19 20
Gnd
-
+
Expansion
1
2
3
Gnd
-
+
Expansion
This section explains how to wire individual devices to the Smart Boiler Expansion 294EXP .
Wiring Instructions
