Viconics C1025 User Manual

ELECTRONIC THERMOSTAT: C1025

FOR MODULATING

ELECTRIC HEAT APPLICATIONS

0 to 10 Vdc modulating output

Vdc pulsed modulating output

Room or supply control applications

DESCRIPTION

The C1025 series thermostats are microcomputer-based,
proportional and integral (PI) devices with one analog 0 to 10
Vdc output and one Vdc tim e proportioning pulsed output.

The analog 0 to 10 Vdc modulating output can control the
room or supply temperature by modulating directly a 0 to 10
Vdc SCR power controller.

The Vdc pulsed output can control the room or supply
temperature by modulating directly 4-32 Vdc triggered solid
state relays ( SSR’s ) using a time proportioning control
algorithm on a 1 second time cycle.

The thermostats also contain two dip switch which adjust the
following parameters :

• Room or supply control applications

• Internal or external remote sensor

Type of output Modulating devices for heating

Modulating analog
0 to 10 Vdc output

SCR’s power controls

Vdc pulsed output 4-32 Vdc triggered SSR’s

DIMENSIONS

BASE

WIRING

FROM TOP

OR FROM BACK

SECURITY SCREW

SPECIFICATIONS

Operating Conditions: -30 °C to 50 °C ( -22 °F to 122 °F )

Control accuracy: ± 0.2 ° C ( ± 0.4 °F ) ( c alibrated )

Proportional band for room

temperature control ( S1 = 0 ): 1.8°C ( 3.2°F )

Proportional band for supply

temperature control ( S1 = 1 ): 28°C ( 50°F )

Analog 0 to 10 Vdc output:

3.275"

( 83 mm )

Sensor: Local 47 K NTC thermistor

Resolution: ± 0.1 °C ( ± 0.2 °F )

Ranges: C1025-02: 10 °C to 32 °C

90

80

70

60

50

0% to 95% R.H. non-condensing

C1025-01: 50 °F to 90 °F

0 to 10 Vdc into 2KΩ resistance min.
5 mA max at 10 Vdc

F

4.5"

( 114 m m )

2.8"

( 71 mm )

1.275"
32 mm

HOW TO ORDER

C1025 -

↓

01 = °F scale

↓

02 = °C scale

Notes: Order remote S61 sensors separately.

Vertical covers are standard.

LIT-C1025-E03

Vdc puls ed output: 20 mA max at 8 Vdc.

Power: 24 Vac -15%, +10% 50/60 Hz; 2 VA

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ANALOG 0 TO 10 Vdc MODULATING OUTPUT

The analog 0 to 10 Vdc modulating output can control the
room or supply temperature by modulating directly 0 to 10
Vdc SCR power controller.

Use only one of the output, not both at the same time.

THERMOSTAT INSTALLATION

Important.
Electronic controllers require special care for wiring and
startup. To avoid problems, carefully follow the
procedures below.

Vdc PULSED MODULATING OUTPUT

The Vdc pulsed output can control the room or supply
temperature by modulating directly 4-32 Vdc triggered solid
state relays ( SSR ) using a time proportioning control
algorithm on a 1 second time cycle.

Ex.:

PI

demand

Time on Time off Total

cycle

50 % ½ sec. ½ sec. 1 sec.
25 % ¼ sec. ¾ sec. 1 sec.

This time proportioning output cannot be used on regular
mechanical relays or contactors.

Use only one of the output, not both at the same time

REMOTE SENSOR

A remote sensor can be wired and used with the C1025
thermostat. To wire a remote sensor, first set dip switch S2 to
position 0 ( off ).

If the application is for discharge air or supply temperature
control, set dip switch S1 to position 1 ( on ). This will enable
a larger proportional band, making the controlled temperature
more stable.

Be sure to have all the literature on hand for all components
installed: controller, actuators, relay, etc...

Look at the wiring diagrams, and study them carefully. Be
sure that you understand how the system is supposed to
work.

Make the wiring according to the wiring diagrams. Respect
polarity for power terminals # 3 & # 4 between multiple
controllers if the same transformer is used.

Remove security screw on left side of thermostat cover.

•

Open up by pulling on the bottom side of thermostat.

•

A) Location:

1- Shouldn’t be installed on outside wall.
2- Must be installed away from any heat source.
3- Shouldn’t be affected by direct sun radiation.
4- Nothing must restrain vertical air circulation to the

thermostat.

Characteristics of remote sensor 47 KΩ ( S61 ).

Temperature °F Temperature °C Sensor resistance

150.0 °F 65.6 °C 9.610 Kohm

140.0 °F 60.0 °C 11.700 Kohm

130.0 °F 54.4 °C 14.342 Kohm

120.0 °F 48.9 °C 17.682 Kohm

110.0 °F 43.3 °C 21.940 Kohm

100.0 °F 37.8 °C 27.412 Kohm

90.0 °F 32.2 °C 34.483 Kohm

80.0 °F 26.7 °C 43.704 Kohm

70.0 °F 21.1 °C 55.834 Kohm

60.0 °F 15.6 °C 71.866 Kohm

50.0 °F 10.0 °C 93.340 Kohm

40.0 °F 4.4 °C 122.298 Kohm

B) Installation:

1- Pull out cables 6” out of the wall.
2- Wall surface must be flat and clean.
3- Separate the thermostat and the base by pulling the

cover by the bottom (same as the security screw.)
4- Insert cable in the central hole of the base.
5- Align the base and mark the location of the two

mounting holes on the wall. Install proper side of

base up.
6- Install shields in the wall.
7- Insert screws in mounting holes on each side of the

base. DO NOT OVERTIGHTEN!
8- Strip each wire 1/4 inch.
9- Insert each wire according to wiring diagram.
10- Reinstall the cover ( top side first ) and gently push

back extra wire length in the hole in the wall.
11- Install security screw.

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