The 3UG3522-1AL20: The 0.1–10 A range covers small motor circuits, pump protection, heater banks, or conveyor drives where you need to detect a loss of load (undercurrent) or a stalled rotor (overcurrent). The single-pole main circuit means it monitors one conductor only — fine for single-phase or DC circuits; for three-phase monitoring you'd need three units or a three-phase relay. The 1 CO contact is rated for AC 230 V control circuits; it can directly switch a PLC input or a contactor coil up to that voltage. The 22.5 mm width is the standard narrow housing for DIN-rail relays — fits alongside terminal blocks and other 22.5 mm modules without wasting panel width.
Siemens 3UG3522-1AL20 SIRIUS Monitoring Relay, 0.1-10A, AC 2
MPN3UG3522-1AL20
Siemens SIRIUS 3UG3522-1AL20 monitoring relay, 22.5mm, undercurrent/overcurrent monitoring, 0.1-10A AC/DC, 1 CO contact, AC 230V 50/60Hz, screw connection.
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026
Specifications
| Parameter | Value |
|---|---|
| Product line / brand name | SIRIUS |
| Parameter | Value |
|---|---|
| Mounting type | snap-on mounting |
| Parameter | Value |
|---|---|
| Ambient temperature during operation | -20 ... +50 °C |
| Reference code acc. to DIN EN 81346-2 | K |
| Number of poles for main current circuit | 1 |
| Product function removable terminal for main circuit | No |
| Product function removable terminal for auxiliary and control circuit | No |
Product details
Frequently asked questions
What replaces 3UG3522-1AL20?
The official replacement is 3UG4622-1AW30. It is a 22.5 mm monitoring relay for undercurrent/overcurrent, 0.1-10 A, 1 CO contact, AC 230 V, with screw terminals — a direct drop-in for the 3UG3522-1AL20.
Can 3UG3522-1AL20 monitor three-phase circuits?
No. It has a single-pole main current circuit and monitors only one conductor. For three-phase undercurrent/overcurrent, you would need three units or a dedicated three-phase monitoring relay.
What is the mounting type for 3UG3522-1AL20?
Snap-on mounting onto a 35 mm DIN rail according to EN 50022. The 22.5 mm housing clips directly onto the rail without tools.
MPN
3UG3522-1AL20