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The control provides either a 4-20 mA or a 0-10 V (dc) output to the boiler. Polarity must be
observed.
• Connect the Mod + terminal from the boiler to terminal 19.
• Connect the Mod - terminal from the boiler to terminal 20.
• Some modulating boilers require an enable to start firing the boiler. Connect the boiler enable to
the stage 1 terminals 21 and 22.
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).
Modutrol IV
tekmar
B
R
W
+
-
tekmar
V9055
+
-
B
R
W
Modutrol IV™
0 - 135
Ω
Actuating
Motor
B
R
W
Mod
+
-
Snow
Melting
Control
670
Modutrol IV™ and V9055™ are trademarks of Honeywell, Inc.
Wiring to a Modulating Boiler
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Modutrol IV
tekmar
B
R
W
+
-
tekmar
V9055
+
-
B
R
W
B
R
W
V9055™
0 - 135
Ω
Actuating
Motor
Mod
+
-
Snow
Melting
Control
670
Wiring to a Single-Stage Boiler
-------------------------------------------------------------------------
-------------------------------------------------------------------------
A single-stage boiler is enabled through the T-T contacts.
• Connect Stage 1 terminals 21 and 22 to the boiler T-T contacts.
Wiring to a Two-Stage Boiler
---------------------------------------------------------------------------
---------------------------------------------------------------------------
A two-stage boiler is enabled through the T-T contacts.
• Connect Stage 1 terminals 21 and 22 to the boiler's stage 1 contacts.
• Connect Stage 2 terminals 23 and 24 to the boiler's stage 2 contacts.
Stage 1
T
T
Boiler 1
21
Stage 1
22
Mod
Enable
T
T
+
-
20
Mod Boiler
19
Boiler 1
21
Stage 1
–
22
+
Stage 2
T
T
Stage 1
T
T
Boiler 1
21
Stage 1
Boiler 1
Stage 2
22 23 24
Modutrol IV
V9055
