1
⁄16 DIN High/Low
Limit Controller
CN3271 Series
F M
APPROVED
U High-Limit, Low-Limit or
High and Low Limits
U Peak Temperature
Detection
U Universal Sensor Inputs
U NEMA 4X (IP65)
Splashproof Faceplate
U Coded Security Levels
U Alarm Inhibit on Power-
Up and Setpoint Change
U Remote Reset Option
The CN3271 Series high-/low-limit
controllers are designed to provide
reliable protection of processes,
process equipment and personnel.
These are UL listed overtemperature
(or undertemperature) controllers,
and are FM approved as limit
controllers. Universal sensor inputs
allow the CN3271 Series used in
temperature, pressure and other
processes. Versatile, easy-to-install
and simple to operate, the CN3271
Series provides all of the limit control
functions and features of larger and
more costly controllers in a spaceefficient, 1⁄16 DIN package. With a
NEMA 4X (IP65) rated faceplate, the
controller is an excellent choice for
washdown environments such as
food processing plants.
The CN3271 Series offers
sophisticated LED displays of
process information such as
shutdown duration in hours and
minutes, and maximum or minimum
process values measured during a
shutdown. Temperature input is field
programmable for °C or °F. Process
input decimal points and range are
programmable from -1999 to 9999.
Additional Features Include
U Power-Up Programming Options—
Select from powering up in power-down
condition, always in alarm, or in the
condition at power-up.
U Limit Acknowledge—
Can acknowledge, even though you are
still in alarm condition (ouput does not
reset until condition cleared), or reset
when not in alarm condition.
U Alarm Output 2 with “Silence” Option—
Used for horn outputs. Output 2 can be
reset before the condition resets.
Specifications
Accuracy: ±0.2% FS
Output #1 Relay: SPDT
contact, 3 A @ 250 Vac
(resistive) limit output,
normally energized
(latching high, low
or high and low)
Output #2 Relay:
NO, SPST contact,
2 A @ 250 Vac
(resistive) normally
energized/normally
de-energized, inhibit on
power-up and setpoint
changes, latching/non-latching (field
selectable: process, deviation, band)
Digital Input Option: Dry contact input,
for remote acknowledgement; RS485,
MODBUS
with “-DI” option
Power: 100 to 240 Vac, 50 to 60 Hz
(24 Vac/dc optional) ±10% nominal
value; consumption, 8 VA
Operating Environment: 0 to 50°C
(30 to 122°F) 20 to 85% relative
humidity non-condensing
®
communications included
Input
-100 to 1000°C (-150 to 1830°F)
-100 to 1370°C (-150 to 2500°F)
-100 to 800°C (-150 to 1470°F)
-200 to 400°C (-330 to 750°F)
-100 to 1400°C (-150 to 2550°F)
Thermocouple -50 to 1760°C (-60 to 3200°F)
0 to 1820°C (32 to 3300°F)
-100 to 900°C (-150 to 1650°F)
-200 to 600°C (-330 to 1110°F)
-100 to 1400°C (-150 to 2550°F)
0 to 2300°C (32 to 4170°F)
RTD, 3-Wire, 100 Ω ,
Process (DC)
To Order Visit omega.com/cn3271 for Pricing and Details
Model No. Description
CN3271-R1 Limit controller,
CN3271-R1-R2 Limit controller,
CN3271-R1-R2-DI Limit controller, dual relays, digital reset input
CN3271-R1-LV Limit controller, single relay, low voltage power
CN3271-R1-R2-LV Limit controller, dual relays, low voltage power
CN3271-R1-R2-DI-LV Limit controller, dual relays, DI reset, low power
CNQUENCHARC
Comes complete with operator’s manual.
Ordering Examples: CN3271-R1-R2-DI, limit controller with dual relays and digital reset input.
CN3271-R1, limit controller with single relay. OCW-2, OMEGACARESM extends standard
3-year warranty to a total of 5 years.
Noise suppression RC snubber (2 leads),
CN3271-R1 shown actual size.
Panel Cutout: 45 mm2 (1.77 in2)
Dimensions: 48 mm
Depth Behind Panel: 105 mm (4.33")
or 122 mm (4.8") with digital input option
Weight: 250 g (8.75 oz)
2
(1.9 in2)
Panel punches
available, visit
omega.com/
panelpunches
/
(J DIN)
(T DIN)
PL II
//
α = 0.00385 -200 to 850°C (-330 to 1560°F)
0 to 20 or 4 to 20 mA, 0 to 60 or
12 to 60 mV, 0 to 5, 1 to 5, 0 to 10,
or 2 to 10 Vdc
1
⁄
16 DIN, single relay
1
⁄
16 DIN, dual relays
110 to 230 Vac
P-101