Tekmar 680 - Page 12

© 2016 680_D - 05/16 12 of 48
Mod Enable
TT+
-
33 34
Mod
Boiler 1
35 36
Stage 1 Stage 2
37 38
+
-
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 33.
• Connect the Mod - terminal from the boiler to terminal 34.
• Some modulating boilers require an enable to start firing the boiler. Connect the boiler enable to
the stage 1 terminals 35 and 36.
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
680
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
680
Wiring to a Single-Stage Boiler -------------------------------------------------------------------------
A single-stage boiler is enabled through the T-T contacts.
• Connect Stage 1 terminals 35 and 36 to the boiler T-T contacts.
33 34
Mod
Boiler 1
35 36
Stage 1 Stage 2
37 38
+
-
Stage 1
TT
Wiring to a Two-Stage Boiler ---------------------------------------------------------------------------
A two-stage boiler is enabled through the T-T contacts.
• Connect Stage 1 terminals 35 and 36 to the boiler's stage 1 contacts.
• Connect Stage 2 terminals 37 and 38 to the boiler's stage 2 contacts.
Stage 2
TT
Stage 1
TT
33 34
Mod
Boiler 1
35 36
Stage 1 Stage 2
37 38
+
-