INSTALLATION DATA
ETC TWO STAGE ELECTRONIC
TEMPERATURE CONTROL
The Ranco® ETC is a microprocessor
based family of electronic temperature
controls, designed to provide on/off
control for commercial heating, cooling,
air conditioning and refrigeration. The ETC
is equipped with a liquid crystal display
(LCD) that provides a constant readout
of the sensed temperature, and a touch
keypad that allows the user to easily and
accurately select the setpoint temperature,
differential and heating/cooling mode
of the operation. Models are available
that operate on either line voltage
(120/208/240V AC) or low voltage (24V AC).
APPLICATIONS
With its wide temperature setpoint range
and selectable heating or cooling modes,
the ETC can be used for a wide variety of
applications including multiple compressor
control, two stage heating, ventilation
control, automatic changeover, condenser
fan cycling, space and return air tempera-
ture control, water cooled condensers and
control with alarm function.
FEATURES
• Wide setpoint temperature range (-30°F to 220°F) and differential
adjustment (1°F to 30°F)
• Simple keypad programming of setpoint temperature, differential and
cooling/heating modes
• Two individually programmable stages for heating and/or cooling
• LCD display readout of sensor temperature, control settings, relay
status and onboard diagnostics
• LED (Light Emitting Diode) backlight to improve visibility of the display
in low light ambient applications.
• IP67 rated (water and dust resistant) thermistor-based probe to
remotely monitor temperature
• The sensor probe can be retrofitted in the field by the use of factory
installed interconnect
• Remote temperature sensing up to 400 feet
• Two SPDT output relays
• User-selectable Fahrenheit/Celsius scales
• Lockout switch to prevent tampering by unauthorized personnel
• Choice of line voltage and low voltage models available
• Optional 0 to 10 volt analog output available for remote temperature
indication
• Anti-short Cycle Compressor Delay for cooling applications
SPECIFICATIONS
Input Voltage
120 or 208/240V AC (24V AC optional), 50/60 Hz
Temperature Range -30°F to 220°F
Differential Range
1°F to 30°F
Switch Action
SPDT
Sensor
Thermistor, 1.94 in. long x 0.25 in. diameter
with 8 ft. cable, IP67 rated
Power Consumption 120/208/240V AC: 100 milliamps
24V AC: 2-6V AC
1
Relay Electrical Ratings
NO Contact
120V
208/240V
Full-load amps
9.8 Amps
4.9 Amps
Locked rotor amps
58.8 Amps 29.4 Amps
Resistive amps
9.8 Amps
4.9 Amps
Horsepower
1/2 HP
1/2 HP
NC Contact
Full-load amps
5.8 Amps
2.9 Amps
Locked rotor amps
34.8 Amps 17.4 Amps
Resistive amps
5.8 Amps
2.9 Amps
Horsepower
1/4 HP
1/4 HP
Pilot Duty: 125 VA at 120/208/240 VAC
Control Ambient Temperature
Operating
-20°F to 140°F (-29°C to 60°C)
Storage
-40°F to 176°F (-40°C to 80°C)
Ambient Humidity
0 to 95%, RH, Non-condensing
0 to 10V Output Impedance 1 K
Enclosure
NEMA 1, Plastic
Agency Approvals
UL Listed, File E94419, Guide XAPX
CSA Certified, File LR68340, Class 4813 02
ETC ORDERING INFORMATION
Uni-Line
OEM
Input
No. of
0 - 10 V
Numbers
Numbers
Voltage
Stages
Output
ETC-211000-000 ETC-211020-000 120/240
2
No
ETC-211100-000
ETC-211120-000
120/240
2
Yes
ETC-212000-000 ETC-212020-000
24
2
No
ETC-212100-000
ETC-212120-000
24
2
Yes
OPERATION
Liquid Crystal Display (LCD)
The LCD display provides a constant readout of the sensor temperature
and indicates if either of the two output relays is energized. When the
S1
annunciator is constantly illuminated during operation, the Stage 1
relay is energized. Likewise, when the S2 annunciator is constantly
illuminated during operation, the Stage 2 relay is energized. The display
is also used with the keypad to allow the user to adjust the setpoint
temperatures, differentials and heating/cooling modes for each stage.
Backlight
When any mode key is pressed, the backlight is activated and the ETC is
in control mode. Press the SET key to begin program mode.
Control Setup
The temperature setpoint refers to the temperature at which the
normally open (NO) contacts of the output relay will open. Determine
the loads to be controlled and the operating modes required for each
stage, cooling or heating.
• When the cooling mode is chosen, the differential is above the setpoint.
The relay will de-energize as the temperature falls to the setpoint.
• Anti-short Cycle Compressor Delay for cooling. After a relay
de-energizes, the ETC will prevent the relay from turning on until a
configurable time has occurred to protect compressor.
• When the heating mode is chosen, the differential is below the setpoint.
The relay will de-energize as the temperature rises to the setpoint.
The ETC two stage control can be set up for two stages of heating, two
stages of cooling or one stage cooling plus one stage heating. Refer to
Figures 1, 2 and 3 for a visual representations of different control setups.
