Robertshaw RANCO ETC Series Quick Start Manual

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 temperature
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
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
INSTALLATION DATA
ElECTroniC TEmpEraTurE
Relay Electrical Ratings
NO Contact
Full-load amps
Locked rotor amps
Resistive amps
Horsepower
NC Contact
Full-load amps
Locked rotor amps
Resistive amps
Horsepower
Pilot Duty: 125 VA at 120/208/240 VAC
Control Ambient Temperature
Operating
Storage
Ambient Humidity
0 to 10V Output Impedance 1K
Enclosure
Agency Approvals
ETC ORDERING INFORMATION
Input
Part Numbers Voltage
ETC-211020-000 120/240
ETC-211120-000 120/240
ETC-212020-000 24
ETC-212120-000 24
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 of the 3 mode keys are 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.
• 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.
1
ETC Two STagE
ConTrol
120V 208/240V
9.8 A 4.9 A
58.8 A 29.4 A
9.8 A 4.9 A
1/2 hp 1/2 hp
5.8 A 2.9 A
34.8 A 17.4 A
5.8 A 2.9 A
1/4 hp 1/4 hp
-20°F to 140°F (-29°C to 60°C)
-40°F to 176°F (-40°C to 80°C)
0 to 95%, RH, Non-condensing
NEMA 1, Plastic
UL Listed, File E94419, Guide XAPX
CSA Certified, File LR68340, Class 4813 02
No. of 0 - 10 V
Stages Output
2 No
2 Yes
2 No
2 Yes