
Specications
Inputs:
Ranges: See Table 1
Impedance: >1 M Ohms
Input Bias Current (burnout detect):
<1.5 microamp
Overvoltage: ±10V differential
Common Mode (Input to Ground):
600VAC or 1000VDC, max
LED Indications:
Input Range (Green)
>100%input:8Hzash
<0%input:4Hzash
Setpoint (Red):
Tripped: Solid red
One LED for each setpoint
Limit Differential (Deadband):
0.25% to 50% of span
Response Time:
Dynamic Deadband:
Relay status will change when
proper setpoint/process condition
exists uninterrupted for 100msec
NormalMode(analogltering):
<250msec, (10-90%)
Pin Connections
1 AC Power (Hot)
2 No Connection
3 AC Power (Neu)
4 Input (+)
5 Input (-)
6 (A) N.O.
7 (A) C
8 (A) N.C.
9 (B) N.O.
10 (B) C
11 (B) N.C.
OMEGA ENGINEERING, INC., warrants this unit to be free of defects in materials and workmanship for a period of 13 months from date of purchase.
omega.com info@omega.
Servicing North America:
U.S.A.:
Omega Engineering, Inc., One Omega Drive,
P.O. Box 4047, Stamford, CT 06907-0047 USA
Toll-Free: 1-800-826-6342 (USA & Canada only)
Customer Service: 1-800-622-2378
(USA & Canada only)
Engineering Service: 1-800-872-9436
(USA & Canada only)
Tel: (203) 359-1660
Fax: (203) 359-7700
e-mail: info @omega.com
For Other Locations Visit
omega.com/worldwide
The information contained in this document is
believed to be correct, but OMEGA accepts no
liability for any errors it contains, and reserves
the right to alter specifications without notice.
com
OMEGA’s WARRANTY adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and shipping
time. This ensures that OMEGA’s customers receive maximum coverage on each product.
If the unit malfunctions, it must be returned to the factory for evaluation. OMEGA’s Customer Service Department will issue an Authorized Return
(AR) number immediately upon phone or written request. Upon examination by OMEGA, if the unit is found to be defective, it will be repaired
or replaced at no charge. OMEGA’s WARRANTY does not apply to defects resulting from any action of the purchaser, including but not limited to
mishandling, improper interfacing, operation outside of design limits, improper repair, or unauthorized modification. This WARRANTY is VOID if
the unit shows evidence of having been tampered with or shows evidence of having been damaged as a result of excessive corrosion; or current,
heat, moisture or vibration; improper specification; misapplication; misuse or other operating conditions outside of OMEGA’s control. Components
in which wear is not warranted, include but are not limited to contact points, fuses, and triacs.
OMEGA is pleased to offer suggestions on the use of its various products. However, OMEGA neither assumes responsibility for any omissions
or errors nor assumes liability for any damages that result from the use of its products in accordance with information provided by OMEGA,
either verbal or written. OMEGA warrants only that the parts manufactured by the company will be as specified and free of defects. OMEGA
MAKES NO OTHER WARRANTIES OR REPRESENTATIONS OF ANY KIND WHATSOEVER, EXPRESSED OR IMPLIED, EXCEPT THAT OF TITLE, AND
ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY
DISCLAIMED. LIMITATION OF LIABILITY: The remedies of purchaser set forth herein are exclusive, and the total liability of OMEGA with respect to
this order, whether based on contract, warranty, negligence, indemnification, strict liability or otherwise, shall not exceed the purchase price of
the component upon which liability is based. In no event shall OMEGA be liable for consequential, incidental or special damages.
CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1) as a “Basic Component” under 10 CFR 21 (NRC), used
in or with any nuclear installation or activity; or (2) in medical applications or used on humans. Should any Product(s) be used in or with any nuclear
installation or activity, medical application, used on humans, or misused in any way, OMEGA assumes no responsibility as set forth in our basic
WARRANTY/DISCLAIMER language, and, additionally, purchaser will indemnify OMEGA and hold OMEGA harmless from any liability or damage
whatsoever arising out of the use of the Product(s) in such a manner.
Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department. BEFORE RETURNING ANY PRODUCT(S) TO OMEGA,
PURCHASER MUST OBTAIN AN AUTHORIZED RETURN (AR) NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT (IN ORDER TO AVOID
PROCESSING DELAYS). The assigned AR number should then be marked on the outside of the return package and on any correspondence.
The purchaser is responsible for shipping charges, freight, insurance and proper packaging to prevent breakage in transit.
FOR WARRANTY RETURNS, please have the following
information available BEFORE contacting OMEGA.
1. Purchase order number which the product was PURCHASED,
2. Model and serial number of the product under warranty, and
3. Repair instructions and/or specific problems relative to
OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible. This affor ds customers the latest
technology and engineering. OMEGA is a registered trademark of OMEGA ENGINEERING, INC.
© COPYRIGHT 2015 OMEGA ENGINEERING, INC. All rights reserved. This document may not be copied, photocopied, translated, or reduced to
any electronic medium-readable form, in whole or in part, without the prior written consent of OMEGA ENGINEERING, INC.
the product.
Setpoint:
Effectivity: Setpoints are adjustable over
100% of input span
Repeatability (Constant Temp):
±0.2% for inputs > 0°C
±0.3% for inputs < 0°C
Stability:
Line Voltage: ±0.01%/%, max
Temperature: ±0.05% of full scale/°C, max.
Common Mode Rejection:
DC to 60Hz: 120dB
Isolation:
1000V DC between contacts, input and
power
ESD Susceptibility:
Meets IEC 801-2, Level 2 (4KV)
Humidity:
Operating: 15 to 95% (@45°C)
Soak: 90% for 24 hours (@65°C)
Temperature Range:
Operating: 0 to 60°C (32 to 140°F)
Storage: -15 to 70°C (5 to 158°F)
Power:
Consumption: 2W typical, 5W max
Standard: Selectable 120/240VAC (±10%,
50-60Hz)
Optional: 9 to 30VDC Inverter-Isolated
Key:
N.O. = Normally Open
C = Common
N.C. = Normally Closed
DC Power: Pin 1 = (+)
Pin 3 = (-)
*
Contacts are in the “normal” state
when the relay is de-energized.
WARRANTY/DISCLAIMER
RETURN REQUESTS/INQUIRIES
FOR NON-WARRANTY RETURNS, consult OMEGA for current repair
charges. Have the following information available BEFORE contacting
OMEGA.
1. Purchase Order number to cover the COST of the repair,
2. Model and serial number of the product and
3. Repair instructions and/or specific problems relative to the product.
Relay Contacts:
1 SPDT (1 Form C) per setpoint
Current Rating (resistive)
120VAC: 5A; 240VAC: 2A; 28VDC: 5A
Material: Silver-Cadmium Oxide
Electrical Life: 105 operations at rated load
Note: External relay contact protection is
required for use with inductive loads.
See relay protection.
Mechanical Life: 107 operations
Latch Reset Time:
5 seconds (with power removed)
Weight: 0.64 lbs
Agency Approvals:
UL recognized per standard UL 508,
(File No. E99775)
SMLA-TC
Thermocouple Input,
Field Configurable Limit Alarms
INSTRUCTION
SHEET
Shop online at omega.comSM e-mail:
[email protected]
For latest product manuals: www.omegamanual.info
FieldCongurableInputRangesforE,J,K,R,S
and T Type Thermocouples
Exclusive “Dynamic Deadband” Prevents False Trips
Burnout Detection
Description
Model SMLA-TC limit alarm offers wide ranging inputs and
exiblesetpointcapability.Itacceptssixpopularthermocouple
types with inputs ranging from -270°C (-454°F) to 1760°C
(3200°F). The SMLA-TC provides two independent setpoint
alarms. The SMLA-TC also includes 0.25%-50% adjustable
deadbands and selectable 120/240VAC power.
Diagnostic LED
Model SMLA-TC is equipped with a dual function diagnostic LED.
The green center LED indicates line power and input signal status.
Active line power is indicated by an illuminated LED. If the center
LED is off, check line power and the wiring connection. If the input
signalisabove100%fullscale,theLEDwillashatapproximately
8Hz.Below0%,theashrateisapproximately4Hz.
Output Selection
The SMLA-TC thermocouple limit alarm features output and
setpoint selection:
SMLA-TC Single/Dual Trip (2 SPDT, 5A)
Setpoints are top accessed multi-turn potentiometers (or option
"P" provides top mounted ten-turn dials).
Operation
The eld congurable SMLA-TC limit alarm setpoints can
be congured for HI, LO, latching or fail-safe trip operation.
Non-latching HI and LO setpoints have respective HI and LO
deadbands. In a tripped condition, the setpoint is exceeded
and the appropriate red LED is lit. The trip will reset only when
the process falls below the HI deadband or rises above the LO
deadband(seegure1).Toresetalatchedsetpointthesignal
must be in the safe region and the line power must be turned
off for at least 5 seconds. For proper deadband operation, the
HI setpoint must always be set above the LO setpoint.
In failsafe operation, the relay is energized when the process
is below a HI setpoint or above a LO setpoint (opposite for
non-failsafe). In the failsafe mode, a power failure results in an
alarm condition.
M5485/0715
Provides Relay Contact Closures
at a Preset Temperature Input Level
Setpoints Programmable HI or LO
Selectable Failsafe/Latching Operation
Selectable 120/240VAC Input Power
(9 to 30 VDC Available)
Dynamic Deadband
The input must remain beyond the setpoint for 100 milliseconds,
uninterrupted, to qualify as a valid trip condition. Likewise, the
input must fall outside the deadband and remain there for 100
milliseconds to return the alarm to an untripped condition. This
effectively results in a “dynamic deadband” - based on time -in
addition to the normal deadband.
Options
U Urethane coating of internal circuitry for protection
from corrosive atmospheres.
P Top mounted, ten-turn dial(s) for setpoint adjustment.
C620 Factory calibration of input range, set points and output
relays. Not available with option P.
Conguration
The factory presets for SMLA-TC are as follows:
SMLA-TC
Input J-type
0-360°C
Burn Out Positive
Output Dual, SPDT
Trip A: HI, B: LO
Latching No
Failsafe No
Deadband A/B: 0.25%
Power 120VAC
Refer to Figure 5 for switch locations.
For other I/O ranges, remove the four base screws and case to
accessthecongurationswitches.
Replace the cover before applying power.

Table 1: SMLA-TC Input Ranges
Figure 1: Limit alarm operation and effect of deadband.
Input
1.UsingTable1,congurepositions1through3ofSW1and
1 through 5 of SW2 for the desired input range. Round desired
maximum/minimum input values to the next highest range (e.g.,
0-300°C = 0-350°C).
2. Choose the desired upscale/downscale thermocouple
burnout detection by setting position 6 of SW2. See Figure 5.
Output
1.Congurepositions4through8ofSW1forthedesiredalarm
functions. See Figure 6.
Power
1.ConguretheACjumpersforeither120or240VACoperation.
See Figure 4.
Calibration
Note:Tomaximizethermalstability,nalcalibrationshouldbe
performed in the operating installation, allowing approximately
1-2 hours for warmup and thermal equilibrium of the system.
Setpoint: Set deadband at its minimum (factory default - fully
CCW) before adjusting the setpoint. With the appropriate
input applied, adjust setpoint until the relay trips. For HI trip
calibration, start with the setpoint above the desired trip. For
LO trip calibration, start below the desired trip.
Figure 2: DC Inductive Loads
Figure 5: SMLA-TC Factory Calibration Type "J" 0-360°C
Figure 3: AC Inductive Loads
Figure 6: Mode Selection; Dual Trip/A: HI, B: LO,
Dual HI/LO, Non-Latching, Non-Failsafe
Mounting
All modules feature plug-in installation. Models SMLA-TC use
an 11-pin base, either molded socket (SKT-SM-11P) or DIN rail socket (SKT-DR-11P).
Dimensions
Dimensions are in millimeters (inches)
ON = Closed
1
2
Range
See Table 1
"A" Hi Trip
"A" Low TripOnOff
"B" Low TripOnOff
Figure 4: 120/240 VAC Selection
3
"B" Hi Trip
45
*
78
6
*
Single Trip (A)
Dual Trip TripOnOff
Non-Failsafe
FailsafeOnOff
Latching
Non-LatchingOnOff
Non-Latching, Non-Failsafe
Deadband: Set deadband to its minimum (factory default - fully
CCW). Set setpoint to desired trip. Adjust input until relay trips.
Readjust deadband to 50% (fully CW). Set input to desired
deadband position. Slowly adjust deadband until relay untrips.
Note that Custom Calibration (option C620) is available from the
factory (settings MUSTbewithinspecications):
a) Input Type (see table)
b) Setpoint A trip point and reset point
c) Setpoint B trip point and reset point
d) Latching (ON/OFF)
e) Failsafe (ON/OFF)
Notethatifadeadbandentryisnotspecied,thedefaultentry
will be used.
Relay Protection and EMI Suppression
When switching inductive loads, maximum relay life and
transient EMI suppression is achieved using external protection
(see Figures 2 & 3). Place all protection devices directly across
the load and minimize lead lengths. For AC inductive loads,
place a properly-rated MOV across the load in parallel with a
seriesRCsnubber.Usea0.01to0.1mFpulselmcapacitor
(foil polypropylene recommended) of sufcient voltage, and
a 47ohm, 1/2W carbon resistor. For DC inductive loads,
place a diode across the load (PRV > DC supply, 1N4006
recommended) with (+) to cathode and (-) to anode (the RC
snubber is an optional enhancement).
Mark II
SKT-SM-11P (Track/Surface)
SKT-DR-11P (DIN Rail)