Watlow Series L Temperature Limiting Controller

Watlow Series L Temperature Limiting Controller

Product series and core positioning

1. Product series division and applicable scenarios

The Watlow Series L series is divided into three sub series: LF, LV, and LS, all of which are industrial grade temperature limit controllers. Its core function is to serve as a redundant safety device for the main control system, independently monitoring temperature and triggering protective actions to prevent equipment damage, product scrapping, or personnel injury caused by thermal runaway. The differences in adaptation scenarios are as follows:

Series Core Features Operating Interface Setpoint Types Applicable Scenarios

The LF series has no operating interface, low cost, no display screen, and no operation keys to fix the set point (customizable at the time of ordering and cannot be modified on site). It does not require on-site adjustment of the set point in scenarios such as standardized production lines and fixed temperature protection for enclosed equipment (such as protection for the heating section of plastic extruders)

The LV series comes with an operation interface that supports on-site adjustment of 4-digit 7-segment LED display screens (displaying set points), ° F/° C indicator lights, ALARM indicator lights, and adjustable set points through rotary encoders/buttons (supporting on-site modification, with "press setting" to prevent misoperation). Scenes that require frequent adjustment of set points, such as food processing equipment (baking ovens, sterilizers), and small laboratory equipment

LS series safety level design, redundant protection only LED status indicator light (no set point display), fixed set point (customizable at the time of ordering, cannot be modified on site), high safety demand scenarios, such as heating equipment that may cause fires (industrial ovens, painting production lines), medical equipment auxiliary heating protection

2. Core values and differentiation advantages

Independent safety protection: completely independent from the main controller, equipped with sensors, power circuits, and output actuators. Even if the main controller fails (such as sensor failure or output adhesion), it can still reliably trigger protection and avoid the risk of "single point failure".

Multi installation adaptation: Supports 1/8 DIN panel installation, DIN rail installation, open circuit board installation, and encapsulation module installation, covering various installation needs from standardized cabinets to customized equipment.

Complete authoritative certifications: The entire series has passed UL 873 (temperature regulator), CSA C22.2 # 24 (temperature control), and FM Class 3545 (temperature limit switch) certifications; The LS series additionally complies with UL/EN 60730-1/2-9 (automatic control for household and similar equipment), suitable for harsh scenarios such as food service and medical assistance.

Wide compatibility of sensors: Supports thermocouples (E/J/K/T type) and RTDs (100 Ω platinum resistors), adapting to different temperature ranges and accuracy requirements, such as K-type thermocouples for high-temperature industrial furnaces (-270~1370 ° C) and T-type thermocouples for low-temperature refrigeration equipment (-270~400 ° C).

Product basic specifications

1. Physical and installation specifications

(1) Installation method and size

Installation type size (width x height x depth) Installation requirements Protection level

1/8 DIN panel installation 72.4mm × 72.4mm × 51.7mm (depth behind the panel) panel opening 72.4mm × 72.4mm, thickness 1.52-3.18mm, requires the use of a matching installation bracket to lock the foundation IP20; Optional NEMA 4X/IP65 with buttons (splash proof, dustproof)

DIN rail installation 78.1mm × 112.3mm × 90.7mm (including rail depth 94.7mm) compatible with 35mm × 7.5mm standard DIN rail (DIN 50022), fixed with a snap on structure IP10 (only prevents solid foreign objects)

Installation of an open circuit board with dimensions of 61.7mm × 61.7mm × 45.1mm requires drilling four 3.2mm installation holes, which should be fixed using M2.5 (# 4) screws without protection (to be installed in a closed cabinet)

The installation of the sealing module requires drilling two 5mm installation holes of 70.1mm × 102.9mm × 46.6mm, and fixing them with M3.5 (# 6) screws to IP65 (corrosion-resistant, splash proof, suitable for humid/dusty environments)

(2) Terminal specifications

Terminal type: Two types of terminals can be selected, specify when ordering:

Quick connect terminals: 6.3mm spacing, compatible with AMP P/N 3-520406-2 (terminals 1/2/6-10) and AMP P/N 2-520405-2 (terminals 3-5), requiring AMP 58078-3 crimping tool.

Removable screw terminal: Supports 12-30 AWG wires, with a stripping length of 8mm and a maximum terminal torque of 0.8 Nm (7 in lb) to avoid damage to the terminal due to over tightening.

Wiring identification: Terminal function labels are affixed on the back, clearly indicating terminal definitions such as power supply (L1/L2), sensor (TC+/TC -, RTD S1/S2/S3), output (COM/NO/NC), reset (RESET), etc.

2. Power supply and environmental adaptability