Circuit Breakers & Protection

Overview

Low Voltage Circuit Protection

Nairobi Power Engineers stocks, integrates and tests high-performance circuit protection devices for LV switchboards, motor control centres, and commercial distribution boards. We supply genuine Air Circuit Breakers (ACBs), Moulded Case Circuit Breakers (MCCBs), Miniature Circuit Breakers (MCBs), Residual Current Devices (RCDs), and Surge Protection Devices (SPDs).

As authorized channel partners for Lovato Electric, ABB, Schneider Electric, and Dorman Smith, we perform cascading and discrimination studies to ensure faults are cleared instantaneously at the local branch without nuisance tripping of upstream supply breakers.

Product Lineup

Equipment & Range Highlights

Lovato Electric • MCCBs

Lovato TMax / DPX MCCB Ranges

Moulded case circuit breakers with thermal-magnetic and electronic trip units, high breaking capacity up to 70 kA, and rotary handle mechanisms.

Current16 A – 1600 A

Breaking Capacity25 kA – 70 kA @ 415V

StandardsIEC 60947-2

Power Incomers • ACBs

Air Circuit Breakers (ACB) up to 6300A

3-pole and 4-pole draw-out ACBs with micro-processor trip units (LSI / LSIG), motorized charging mechanisms, and Modbus communications.

Rating630 A – 6300 A

Fault Withstand50 kA / 3s • 100 kA / 1s

ExecutionDraw-Out / Fixed

Lovato SG Series • Surge Protection

Lovato Class I+II Surge Protection (SPD)

Modular plug-in surge arresters engineered to protect sensitive electronics against direct lightning discharges and utility switching overvoltages.

TypeType 1 + Type 2

Iimp12.5 kA – 25 kA (10/350µs)

Imax40 kA – 100 kA (8/20µs)

Breaker Reference

Circuit Protection Technical Data

Device Family	Rated Current (In)	Breaking Capacity (Icu)	Protection Types
Air Circuit Breakers (ACB)	630 A – 6300 A	50 kA – 120 kA @ 415V	L, S, I, G, Earth Fault & Zone Selective Interlocking
Moulded Case (MCCB)	16 A – 1600 A	25 kA – 100 kA @ 415V	Thermal-Magnetic, Electronic LSI, Motor Protection
Miniature Breakers (MCB)	0.5 A – 125 A	6 kA, 10 kA, 15 kA @ 230/400V	Overcurrent & Short Circuit (B, C, D Curves)
Residual Current (RCCB/RCBO)	6 A – 100 A	6 kA – 10 kA / 30mA, 100mA, 300mA	Earth Leakage & Electrocution Shock Protection (Type A / AC)
Surge Arresters (SPD)	Up to 100 kA Imax	Class I (10/350µs) / Class II (8/20µs)	Transient Overvoltage & Lightning Surge Diversion

Key Features

Engineering & Build Highlights

Complete range of 3-pole and 4-pole breakers for TN-S, TN-C-S, and IT network configurations
Comprehensive accessories: shunt trips, undervoltage releases, auxiliary contacts, and motor mechanisms
Type-tested cascading tables to reduce downstream breaker ratings safely without compromising clearance
Lovato Earth leakage relays with external core balance toroid sensors for large feeder circuits
Lockable rotary handles and mechanical door interlocks for maximum operator safety during maintenance

Applications

Target Applications & Sectors

Main LV switchboard transformer incomersStandby generator incomers & bus couplersCommercial tenant sub-distribution feedersIndustrial motor branch circuitsData centre critical power distribution pathsSolar inverter AC collector panelboards

FAQs

Type B trips at 3-5x rated current (resistive loads, domestic lighting); Type C trips at 5-10x rated current (commercial lighting, small motors); Type D trips at 10-20x rated current (high inrush transformers, heavy motors, welding sets).

Yes. We provide manufacturer Type 2 coordination tables combining our Lovato MCCBs/MPCBs, contactors, and overloads to guarantee zero damage after fault clearance.