8
type 258
Do not apply
power here!
Maximum 24 Volts
10A
Safety Divider
24
Vac
120
or
240
Vac
External 24Vac
60Hz class II
transformer
System Pump
Relay
closes to turn on
System Pump
10K Zone
Control
(optional)
Unoccupied
Switch (optional)
to switch control to
Unoccupied mode
Outdoor
Sensor
070
Supply
Sensor
071
26
27
28
29
30
UnO
Sw
Com
Sen
10K
Zone
Sup
Sen
Out
Sen
6
7
8
5
1
2
3
4
Dem
10A
9
10
10A
11
12
10A
13
14
10A
15
16
Safety Divider
Stage
1
2
3
4
Stage
Stage
Stage
2
1
3
4
Dem
10A
17
18
10A
19
20
10A
21
22
8A
23
24
Stage
5
6
7
8
Stage
Stage
N/C
6
5
7
8
C
R
Power
Pmp Pmp
System
Comb.
air
25
8
Com N/O
Boiler Relays
close to turn on boilers
10A
Combustion
air Relay
closes to operate
Combustion air damper
Heat Demand
Apply a 24Vac signal
to request heat
to the system
Heat
Connect the stage 1 boiler circuit to terminals
Stage 1 (9
and 10). These terminals lead to a 10 amp dry relay
contact which closes when the control requires boiler
operation. Repeat this step with the correct terminals for
each additional stage. Boilers with 24Vac control circuits
can be switched directly through the control. If higher
voltages are used, isolation relays must be added.
8
9
10
11
12
13
14
15
16
Stage
1
2
3
4
Stage
Stage
Stage
2
1
3
4
17
18
19
20
21
22
23
24
Stage
5
6
7
8
Stage
Stage
N/C
6
5
7
8
b.
r
25
8
Com N/O
Powered input connections
If a 24Vac external
Heat Demand signal is used, (zone valve end switches, etc.) connect
the wiring from the Heat Demand circuit to terminals
Heat Dem (5 and 6). When 24Vac
is applied to these terminals, the control will recognize a "call for heat" from the system.
DIP switch must be set to "Reset"
If a 24Vac
Setpoint Demand signal is used, (aquastat, etc.) connect the wiring from the
Setpoint Demand circuit to terminals
Heat Dem (5 and 6). When 24Vac is applied to these
terminals, the control will recognize a "call for Setpoint temperature" and switch into
Setpoint mode.
DIP switch must be set to "Stpnt"
6
7
8
5
Dem
9
10
11
12
13
Stage
1
2
3
Stage
2
1
Dem
Comb.
air
Heat
Sensor and unpowered input connections
Power should never be applied to these terminals.
Damage to the control will result.
Connect the two wires from the Outdoor Sensor 070 to terminals
Com Sen — Out Sen (28 and 30).
Connect the two wires from the Supply Sensor 071 to terminals
Com Sen — Sup Sen (28 and 29).
Do not apply power here!
26
27
28
29
30
UnO
Sw
Com
Sen
10K
Zone
Sup
Sen
Out
Sen
26
27
28
29
30
UnO
Sw
Com
Sen
10K
Zone
Sup
Sen
Out
Sen
Option: Indoor temperature feedback, tekmar 10K Zone Control Only
Connect the two wires from a tekmar 10K Zone Control to terminals
10K Zone — Com Sen (27 and 28).
Option: Occupied/Unoccupied switch input, when not using Internal timer
Connect the two wires from the Occupied/Unoccupied dry contact switch
(timer, relay, etc.) to terminals
UnO Sen — Com Sen (26 and 28).
26
27
28
29
30
UnO
Sw
Com
Sen
10K
Zone
Sup
Sen
Out
Sen
26
27
28
29
30
UnO
Sw
Com
Sen
10K
Zone
Sup
Sen
Out
Sen
Electrical connections to the terminal plugs of the 258 control. Control relays are shown in "power down" condition.
Note: This is not a Wiring Diagram.
For a detailed wiring schematic of
your specific application, refer to the Application Brochure A 258.
