Toshiba Corporation RC81A Ground Fault Module

Description:

The Toshiba RC81A Ground Fault Module is used with Toshiba RC800 and RC820 Type 2E motor protection relays to provide zero-sequence ground fault detection for three-phase motor control systems. Commonly installed in motor control centers (MCCs), pump stations, compressors, conveyor systems, mining equipment, water and wastewater treatment facilities, and industrial process machinery requiring adjustable ground fault protection. Maintenance teams, OEMs, and system integrators use this module for replacement of failed ground fault modules, motor protection upgrades, preventive maintenance, and control panel retrofits.

Applications:

The Toshiba RC81A is widely used in industrial motor starters, conveyor systems, pumping stations, compressors, HVAC equipment, mining operations, chemical processing plants, and factory automation systems where zero-sequence ground fault monitoring protects motors and electrical equipment from insulation failures and ground fault conditions.

Technical Specifications:

• Manufacturer Part Number (MPN): RC81A
• Brand: Toshiba
• Product Type: Ground Fault Module
• Compatible Relay Series: Toshiba RC800 / RC820 Type 2E Motor Protection Relays
• Protection Function: Zero-Sequence Ground Fault Detection
• Ground Fault Current Setting: 4–12 A (ZCT Primary)
• Maximum Ground Fault Current: 60 A
• Ground Fault Time Adjustment: 0.1–1.0 Seconds
• Output Signal: Uses Basic 2E Relay Output Contacts
• Trip Indication: LED with Manual Reset
• Zero Sequence Current Transformer (ZCT): 12 A : 40 mA, 300 Ω Connected Impedance
• Installation: Plug-In Optional Module for 2E Relay
• Mounting: Motor Control Center (MCC) / Control Panel
• Application: Three-Phase Motor Ground Fault Protection

Common Replacements:

• Toshiba RC81C
• Toshiba RC820-RC81A
• Toshiba RC800-RC81A