` SR535 Alarm Unit - Alpha Controls & Instrumentation Inc.

SR535 Alarm Unit

Alarm unit with Pt100 input and 4-20 mA output

This product is no longer available. Please contact us today
at 800-567-8686 for alternative solutions.

Can We Help You?


Our product experts are here to help you find the right solution for your application!

SR535 is designed for monitoring Pt100 signals in the process industry. The unit gives alarm functions for either increasing or decreasing temperatures and for certain error states.

SR535 provides a temperature linear output signal, 4-20 mA, corresponding to the measurement range.

• Direct Pt100 input
• 4-20 mA output
• One temperature monitoring relay
• One error monitoring relay
• Reliable and interference free safety alarm without false alarms
• High configuration flexibility with solder jumpers
• Adjustable time delay, hysteresis and relay functions
• Available for AC or DC power supply
• DIN-rail mounting
• Plug-in screw terminals

Input Pt100 (acc. to IEC 60751) 3-wire connection
Range 0-100, 0-150, 0-200, 0-300, 0-500 C
Sensor current 3 mA
Output Relay 1 Temperature monitoring 1-pole switch over contact
Selectable High or Low alarm Jumpers on PCB (standard: High)
Adjustable alarm set-point Front 15-turn potentiometer / test connector
Selectable alarm delay 0.4 s (standard) or 2 s, changeable on PCB
Selectable hysteresis 0.5 % (standard) or 5 %, changeable on PCB
Selectable normally active or passive function Jumpers on PCB (standard: normally active)
Output Relay 2 Error monitoring, 1-pole opening contact
Fixed, normally active and opening contact Alarm at power failure, sensor break or high input (125 %)
Output Current 4-20 mA linear to selected temperature range
Operation temperature -20 to +60 C / -4 to +140 F
Input to relay outputs 3 700 VAC, 1 min
Input to AC power supply 3 700 VAC, 1 min
Input to DC power supply 1 500 VAC, 1 min
Relay outputs to power supply 3 700 VAC, 1 min
Input to mA output Not isolated
AC versions 230 VAC, -15..+10 %, 45..75 Hz; 115 VAC, -15..+10 %, 45..75 Hz
DC version 19 to 60 VDC
Typical accuracy Trip point, mA output, 0.1 % of span
Connections Plug-in terminals Stranded, ≤ 2.5 mm2, AWG 14
Mounting Rail acc. to DIN EN 50022, 35 mm