How to Select the Right Low Voltage Electrical Product — A Practical Guide

Choosing the right low voltage electrical product is not only about price — the wrong rating can cause nuisance tripping, coil burnout or even fire risk. This guide summarises the key selection points for the product families we manufacture, so you can shortlist the correct model before sending us an inquiry.

1、AC Contactor (CJX2 series)

. Match the AC-3 rated current to your motor's full-load current, with a 20-30% margin for frequent starting.

. Confirm the coil voltage exactly (24/110/220/380 V AC) — this is the most common reason for field failures.

. For capacitor switching or heavy inductive loads, tell us the application; we will suggest the appropriate contactor class.

2、Miniature Circuit Breaker (MCB)

. Select the rated current from 1-63 A according to cable size, never the other way round.

. Curve B for resistive loads, Curve C for general motor/lighting circuits, Curve D for high inrush equipment.

. Check the breaking capacity (our M7 series is 6 kA per IEC 60898-1) against your installation's prospective fault current.

3、Residual Current Device (RCCB / RCBO)

. 30 mA for personal protection in residential circuits; 100/300 mA for fire protection and distribution levels.

. Decide between 2-pole (single phase) and 4-pole (three phase) before ordering. All our L8 series comply with IEC 61008-1.

4、Thermal Overload Relay (LR2-D series)

. Set the dial to the motor full-load current, typically within the relay's adjustment range (each frame covers a current band, e.g. D2353/D2355).

. Match the relay frame to the associated CJX2 contactor for direct mounting.

5、Current Transformer (KCT series)

. Primary current should be 20-30% above the maximum load current (200/5 A up to 500/5 A are the most requested ratios).

. Confirm accuracy class: 0.5 for metering, 1 for general indication.

6、Power Capacitor (BSMJ series)

. Size the kvar bank from your measured power factor and target (most utilities require 0.90 or better).

. Confirm rated voltage against your network (450 V types cover most 380-420 V networks with margin).

7、Counters, Hour Meters & Specialties

. For counters: mechanical vs. electronic, digits required, and whether the reset must be front-panel operated.

. For hour meters: DC or AC supply, panel cut-out size, and display type (LCD preferred for readability).

Still not sure which model fits? Send us your load schedule or the old product's nameplate photo — our engineers reply within 24 hours with the recommended model and a quotation. See the Contact Us page for phone, WhatsApp and email.