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SIEMENS 3UB88234CW2 overload relay compact unit screw terminals

SIEMENS

SIEMENS 3UB88234CW2 Overload Relay 3 A 12 A 690V AC

SKU CH-Z4T5-T8399

Protects motors from 3 A to 12 A at up to 690 V AC with selectable trip classes 10, 20, 30 and auto or manual reset

  • TypeIndustrial Electrical Controls & Automation
  • Wide 3 A to 12 A protection range
  • Adjustable trip class 10, 20, 30 settings
  • 690 V AC rating for industrial supply
  • Auto and manual reset modes included
  • Direct contactor mounting with screw terminals

SIEMENS 3UB88234CW2 Overload Relay

The SIEMENS 3UB88234CW2 is an overload relay designed for motor protection in industrial control circuits. It suits maintenance engineers and panel builders wiring starters that require adjustable thermal protection up to 690V AC. This device mounts directly to compatible contactors and provides both automatic and manual reset options for flexible recovery after a trip event. It is not for installers who need built-in thermal units or a defined NEMA size rating.

Installation and common issues

Direct-to-contactor mounting simplifies installation on Class 14 starters and Class 48 overload relays using screw terminals for secure wiring. The 1NO/1NC auxiliary contact form supports standard control-circuit feedback without extra accessories. A frequent issue is selecting the wrong trip class; this unit offers 5, 10, 20 and 30 settings, so the correct class must be set to match the motor acceleration profile. Incorrect current setting within the 3 A to 12 A range can also cause nuisance tripping or failed protection.

Adjustable current range 3 A to 12 A

The decisive specification is the adjustable overload relay current setting spanning 3 A minimum to 12 A maximum. This range determines whether the relay matches the full-load current of the specific motor being protected. Trip class selection among 5, 10, 20 and 30 further refines the thermal response but the current window is the primary filter for correct part selection.

Highlights

  • Wide 3 A to 12 A protection range
  • Adjustable trip class 10, 20, 30 settings
  • 690 V AC rating for industrial supply
  • Auto and manual reset modes included
  • Direct contactor mounting with screw terminals

Specifications

BrandSIEMENS
TypeIndustrial Electrical Controls & Automation

Questions about this item

How do I confirm the overload relay is working correctly after wiring it to a contactor?

Apply a test current between the 3 A minimum and 12 A maximum settings, then verify the 1NO/1NC auxiliary contacts change state according to the selected trip class of 10, 20 or 30.

What comes in the box and do I need separate thermal units or a contactor?

The relay includes screw terminals for direct contactor mounting; thermal units are not applicable and the contactor must be purchased separately.

Which trip class should I select for a Class 14 starter application?

Choose trip class 10, 20 or 30 to match the motor acceleration time; all three are compatible with Class 14 starters and Class 48 overload relays.

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