SR535 (Discontinued)
Alarm Unit with Pt100 Input and 4-20 mA Output
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
Technical Specification
| 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 |
| Galvanic isolation | |
| 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 |
| Power supply | |
| 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 |