Watlow LF Series Basic Limit Controller

Watlow LF Series Basic Limit Controller

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 M# input impedance

• 250 nV input referenced error per 1# source resistance

RTD

• 2-wire platinum, 100#

• 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

1. • 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)
2. • 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

SERIES LF (including potted version)

• UL® 873 recognized temperature regulator

• UL® 197 reviewed for use in cooking appliances

• UL® 991

• ANSI Z21.23 gas appliance thermostat approval

• CSA C22.2 #24 approved limit control

• FM Class 3545 temperature limit switches

• RoHS, W.E.E.E.

Terminals

• 0.25 in. (6.3 mm) quick connect, push on terminal or removable screw terminals

Power

• 24VAC +10%; -15%; 50/60Hz, ±5%

• 120VAC +10%; -15%; 50/60Hz, ±5%

• 230 to 240VAC +10%; -15%; 50/60Hz, ±5%

• 10VA max. power consumption

• Data retention upon power failure via nonvolatile memory

Operating Environment

• 32 to 158°F (0 to 70°C)

• 0 to 90% RH, non-condensing

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

Dimensions

• DIN-rail model can be DIN-rail or chassis mount DIN-rail spec DIN 50022, 1.38 in. x 0.30 in. (35 mm x 7.5 mm)