Honeywell MTL4521 Loop Powered Solenoid/Alarm Driver

Overview

The MTL4521 is a loop-powered solenoid and alarm driver from Honeywell’s MTL4500 Series. It controls intrinsically safe loads such as solenoids, alarms, and LEDs. This module connects hazardous-area field devices with safe-area control systems. It is ideal for Zone 0, IIC, T4 hazardous areas and Division 1, Group A locations. The compact module mounts easily on a standard DIN rail.

Technical Specifications

• Model: MTL4521

• Function: Solenoid/alarm driver, loop-powered

• Input Type: 4–20 mA loop signal from control system

• Output Type: Drives certified intrinsically safe loads (solenoids, alarms, LEDs)

• Power Supply: Loop-powered, no external power required

• Maximum Output Power: 0.68 W

• Maximum Voltage (Um): 253 V AC or DC

• Isolation: 3-port isolation between input, output, and power

• Mounting: DIN rail

• Safety Rating: SIL3 for de-energize output, SIL1 for energize output per IEC 61508

• Operating Temperature: -20°C to +60°C typical

• Number of Channels: One

• Load Location: Zone 0, IIC, T4 hazardous area if certified

• Div. 1, Group A: Suitable for hazardous locations

• Input Voltage Range: 20–35 V DC

• Hazardous-Area Output: Minimum voltage 13.6 V at 48 mA, maximum 24 V from 180 Ω

• Current Limit: 48 mA

• Output Ripple: Less than 0.5% of maximum output, peak to peak

• Response Time: Output reaches within 10% of final value in 100 ms

• LED Indicator: Yellow, lights when output is active

• Maximum Current Consumption: 90 mA at 24 V

• Power Dissipation: 1.4 W at 24 V