SERIES LF

Specifications

Limit Controller

• Microprocessor based, limit controller

• Nominal switching hysteresis, typically 3°F (1.7°C)

• High or low limit, factory selectable

• Latching output requires manual reset upon over or

under temperature condition

• Manual or automatic reset on power loss, factory

selectable

• External customer supplied momentary reset switch

• Input filter time: 1 second

Standard Conditions For Specifications

• Rated line voltage, 50 to 60Hz, 0 to 90% RH

non-condensing, 15-minute warm-up

• Calibration ambient range: 77°F (25°C) ±3°C

Sensor Input

Thermocouple

• Grounded or ungrounded

• Type E, J, K, T thermocouple

• >10 MΩ input impedance

• 250 nV input referenced error per 1Ω source resistance RTD

• 2-wire platinum, 100Ω

• DIN-curve (0.00385 curve)

• 125μA nominal RTD excitation current

Input Accuracy Span Range

Type E: -328 to 1470°F (-200 to 800°C)

Type J: 32 to 1382°F (0 to 750°C)

Type K: -328 to 2282°F (-200 to 1250°C)

Type T: -328 to 662°F (-200 to 350°C)

RTD (DIN) -328 to 1472°F (-200 to 800°C)

Thermocouple Input

• Calibration accuracy: ±1% of input accuracy span,

±1° at standard conditions and actual calibration

ambient. Exception: Type T, ±2.4% of input accuracy

span for -328 to 32°F (-200 to 0°C)

• Temperature stability: ±0.3° per degree change in ambient

RTD Input

• Calibration accuracy ±1% of input accuracy span

±1° at standard conditions and actual calibration ambient

• Temperature stability: ±0.2° per degree change in ambient

Allowable Operating Ranges

Type E: -328 to 1470°F (-200 to 800°C)

Type J: -346 to 1900°F (-210 to 1038°C)

Type K: -454 to 2500°F (-270 to 1370°C)

Type T: -454 to 750°F (-270 to 400°C)

RTD (DIN) -328 to 1472°F (-200 to 800°C)

Output Types

Electromechanical Relay, Form C

• Min. load current: 100mA

• 8A @ 240VAC or 30VDC max., resistive

• 250VA pilot duty, 120/240VAC max., inductive

• Use RC suppression for inductive loads

• Electrical life 100,000 cycles at rated current

External Reset Switch

• Momentary, dry contact closure

Agency Approvals SERIES LF (potted version only)

• UL® 991 recognized temperature limit for cooking industry

• UL® 60730-1

Features and Benefits

Fixed set points

• Provides tamper-proof operation

Multiple mounting options

• Minimizes installation time

High or low limit with auto or manual reset

• Provides application flexibility

Fahrenheit or Celsius operation with indication

• Offers application flexibility

Sensor break protection

• Provides positive system shutdown

Agency approvals

• Meets certification requirements/compliance

Microprocessor based technology

• Ensures accurate, repeatable control

Watlow’s family of microprocessor- based limit controllers

provide an economical solution for applications requiring

temperature limit control. Limits are available in a broad

range of packaging options, allowing selection of the best

version for an individual application. Controllers are

available without an operator interface and can be

ordered in square 1/8 DIN-panel mount, DIN-rail mount or

open board design configurations.

The SERIES LF limit family incorporates a microprocessor

design platform. This design provides significant

improvements in the performance, repeatability and

accuracy offered by Watlow’s current line of analog basic

temperature controllers.

The SERIES LF limit offers fixed set points and can be

supplied with or without an operator interface. Operating

set point temperature values are customer defined in the

product configuration

part number.

The LF limit controllers are factory mutual (FM) approved

with special UL® approval for the open board potted

versions. Watlow’s limit controllers include industry

leading service and support and are protected by a

three-year warranty.

EZ-ZONE RM

Additional Key Functions

• Configuration communication port (standard bus)

• Removable modules and connectors

• Ring lug and front-screw terminal options

• Profile ramp soak with 400 total steps

• Retransmit and remote set point input virtually inside

controller eliminating costs for input/output hardware

• User configuration settings can be stored and recalled

• Thermistor input

• Elevated operating range of 0 to 149°F (-18 to 65°C)

• UL® listed, CSA, CE, RoHS, W.E.E.E., FM,

SEMI F47-0200, Class 1, Div. 2 rating on selected

models

Common Specifications (Applies to all models)

Line Voltage/Power

• 20.4 to 30.8VAC/VDC, 50/60Hz ±5%

• Any external power supply used should comply with a

Class 2 or SELV rating (see specific module

specification listing for max. VA power consumption)

• Data retention upon power failure via non-volatile

memory

• Compliant with Semi F47-0200, Figure R1-1 voltage

sag requirements

Environment

• 0 to 149°F (-18 to 65°C) operating temperature

• -40 to 185°F (-40 to 85°C) storage temperature

• 0 to 90% RH, non-condensing

Functional Operating Range for RMC, RMH, RML

and RMS

Type J: -346 to 2192°F (-210 to 1200°C)

Type K: -454 to 2500°F (-270 to 1371°C)

Type T: -454 to 750°F (-270 to 400°C)

Type E: -454 to 1832°F (-270 to 1000°C)

Type N: -454 to 2372°F (-270 to 1300°C)

Type C: 32 to 4200°F (0 to 2315°C)

Type D: 32 to 4200°F (0 to 2315°C)

Type F: 32 to 2449°F (0 to 1343°C)

Type R: -58 to 3214°F (-50 to 1767°C)

Type S: -58 to 3214°F (-50 to 1767°C)

Type B: 32 to 3300°F (0 to 1816°C)

RTD (DIN): -328 to 1472°F (-200 to 800°C)

Process: -1999 to 9999 units

Advanced PID control algorithm

• Offers TRU-TUNE®+ adaptive control to provide tighter

control for demanding applications

• Enables auto-tune for fast, efficient start-up

Communication capabilities

• Provides a range of protocol options including

universal serial bus (USB) device port, Modbus® RTU,

EtherNet/IP™, Modbus® TCP, DeviceNet™ and

PROFIBUS

USB port

• Provides data log retrieval

SPLIT-RAIL control

• Allows modules mounted in separate high-voltage

and low-voltage cabinets to function as an integrated

system

• Minimizes the length and cost of wire runs and

improves system reliability by locating inputs closer to

sensors and outputs closer to loads

AUTO CLONE

• Reduces time and configuration complexity by

automatically building a new module with the same

parameter settings as the replaced module

SENSOR GUARD

• Prevents unplanned process shutdowns and product

loss by switching to a backup sensor if the primary

sensor fails

Benefits of using an integrated controller solution:

• Reduces wiring time and termination complexity

compared with connecting multiple discrete products

• Improves system reliability

• Reduces termination and installation cost

• Eliminates compatibility issues often encountered with

using various discrete components and brands

• Reduces troubleshooting time and downtime costs

because the system can specifically identify any

problems with a sensor, controller, solid state relay

(SSR) power output or heater load

• Complete thermal solution saves engineering

time and labor costs while shortening project

schedules

Features and Benefits

Multiple inputs; from one to 152 PID loops of

control or monitor up to 256 analog inputs

• Mix and match I/O to fit any application; from one

input with two outputs to 152 analog inputs with

152 outputs, or monitor up to as many as 256 analog

inputs all in one system

• Reduces cost because only required loops are

purchased

• Allows a common controller platform across many

design applications as both loops and outputs can

be ordered in single increments

The EZ-ZONE RM controller simplifies thermal system

management. The EZ-ZONE RM controller family is

comprised of six module types: An integrated on-off or

PID control, monitoring and over/under temperature limit

module, a high-density on-off or PID control module,

a high-density limit only module, an input/output (I/O)

expansion module, a high-density monitor/scanner

module and a data logging and field communications

access module. A system is configured by connecting

any combination of module types to address specific

application needs. The EZ-ZONE RM is extremely flexible

and scalable allowing mixing and matching of I/O to

configure one to 152 control loops and up to 256

monitor points.

Now Watlow’s EZ-ZONE RM is available through

Watlow SELECT®, a program that enables you to quickly

identify, configure and receive your thermal products

faster and easier than ever before. 

Optional integrated controller functions can be

combined or ordered in different quantities:

• PID control loops

• Over/under temperature limit control loops

• 10 and 15 ampere power output/heater driver options

• On-board data logging

• Current measurement input

• Sequencer start up and control function

• Programmable timer and counter functions

• Programmable math and logic options

• Multiple communication protocol options

• Mobile configuration with removable secure digital (SD)

flash card

Controller

• User selectable heat/cool, on-off, P, PI, PD, PID or

alarm action, not valid for limit controllers

• Auto-tune with control algorithm

• Control sampling rates: Input = 10Hz, outputs = 10Hz

• Input and output capacity per controller type ordering

information

Serial Communications

• Isolated communications

• Standard bus configuration protocol

Wiring Termination—Touch-Safe Terminals

• Input, power and controller output terminals are touch

safe removable 12 to 22 AWG

Universal Input

• Thermocouple, grounded or ungrounded sensors,

greater than 20MΩ input impedance, 2kΩ source

resistance max.

• Non-isolated to switched dc and process output

• RTD 2- or 3-wire, platinum, 100Ω @ 0°C calibration to

DIN curve (0.00385 Ω/Ω/°C)

• Process, 4-20mA @ 100Ω, or 0-10VDC @ 20kΩ input

impedance; scalable

High-amperage power control output (1/16 DIN only)

• Drives 15 ampere resistive loads direct

• Reduces component count

• Saves panel space and simplifies wiring

• Reduces cost of ownership

PM LEGACY™

Specifications

Line Voltage/Power

• 85 to 264VAC, 47 to 63Hz

• 20 to 28VAC, +10/-15%; 50/60Hz, ±5%

• 12 to 40VDC

• 10VA (1/32 and 1/16 DIN)

• Data retention upon power failure via non-volatile

memory

• Compliant SEMI F47-0200, Figure R1-1 voltage sag

requirements @ 24VAC or higher

Environment

• 0 to 149°F (-18 to 65°C) operating temperature

• -40 to 185°F (-40 to 85°C) storage temperature

• 0 to 90% RH, non-condensing

Accuracy

• Calibration accuracy and sensor conformity: ±0.1%

of span, ±1°C @ the calibrated ambient temperature

and rated line voltage

• Type S: 0.2%

• Type T below -50°C: 0.2%

• Calibration ambient temperature @ 77°F ±5°F

(25°C ±3°C)

• Accuracy span: 1000°F (540°C) min.

• Temperature stability: ±0.1°F/°F (±0.1°C/°C) rise in

ambient max.

Agency Approvals

• cULus® UL®/EN/CSA C22.2 No 61010-1 Listed,

File E185611

• CSA C22.2 No. 24, File 158031

• UL® 50 4X indoor locations, NEMA 4X, IP66,

IP67 front seal

• cULus® ANSI/ISA 12.12.01-2007, CSA-C22.2 No.

213-1987, Class 1, Div. 2, Groups A, B, C and D,

temperature code T4A, File E184390 (optional)

• CE, RoHS by design, W.E.E.E.

• FM Class 3545 (limit controls)

The PM LEGACY™ series panel mount controller is an

industry leading PID controller that allows optimal performance

utilizing simple control and menu functionality

without complex features. It is ideally suited for basic

applications and usage levels.

The LEGACY includes one universal input and an option

for up to two outputs and is available in 1/32. and 1/16

DIN panel mount packages. It can be ordered as a PID

process controller or as a dedicated over and under-temperature

limit controller.

Agency approvals: UL® listed, CSA, CE, RoHS,

W.E.E.E., FM, SEMI F47-0200. Class 1. Div. 2 rating

on selected models

• Assures prompt product acceptance

• Reduces end product documentation costs

P3T armor sealing system

• Complies to NEMA 4X, IP66 and IP67 specifications

• Allows controller to be cleaned and washed

• Certified UL® 50 independent to NEMA 4X

specification

Consistent Termination Labeling (CTL) connection

system

• Simplifies switching between products

• Speeds up user’s system documentation

Three-year warranty

• Demonstrates Watlow’s reliability and product support