CHINT NCH8 Modular AC Contactor, 20-63 A

A DIN-rail modular contactor for lighting, heating and small motor loads

The NCH8 is a modular AC contactor from CHINT for 20, 25, 40 and 63 A loads on 230 or 400 V. It is built in the 18 mm and 36 mm module widths, so it sits beside breakers in a distribution board and switches lighting groups, heaters, pumps and small motors from a control signal. The catalog lists utilization categories AC-1, AC-7a, AC-7b and AC-3 and describes silent operation.

Technical specifications

Choosing the rating and coil

For resistive heating and lighting use the AC-1 or AC-7a current. For motors the AC-3 figure is much lower, so a 20 A NCH8 is a 9 A motor contactor, and a catalog table lists the lamp count by unit power, for example 20 tungsten 60 W lamps on a 20 A unit. Derate for the board temperature using the heating-current table, and add an overload relay for motor duty. The coil voltage is part of the order code, so state it with the contact arrangement.

What to confirm before ordering

Send the rated current, the contact arrangement, the coil voltage and the load type. For larger loads compare the Schneider TeSys D LC1D or the ABB AF09, or see the contactors and overload relays category.

How the CHINT NCH8 contactor works

A contactor is an electrically operated switch. A small control signal energizes the coil, and the coil closes the power contacts to switch a much larger load. The NCH8 packs this into an 18 mm or 36 mm DIN-rail module, so it sits next to miniature breakers in a distribution board. The 2P versions up to 25 A are 18 mm wide, while the 4P versions and the 40 and 63 A frames are 36 mm wide. The catalog describes silent operation, which matters in residential and commercial boards. The coil closes the contacts within 85 to 110 percent of the rated control voltage Us and releases them between 20 and 75 percent of Us.

Applications of the NCH8

• Lighting groups in offices, shops, car parks and public buildings, including tungsten lamp banks
• Resistive heating and water heaters switched from a thermostat or timer
• Small pumps and fans on 230 or 400 V supplies, using the AC-3 rating
• Remote or automatic switching from a building management system, a time switch or a PLC

Selection checklist for the NCH8

• Current: choose from 20, 25, 40 or 63 A. For resistive and lighting loads use the AC-1 or AC-7a rating.
• Motor duty: the AC-3 current is lower. The NCH8-20 and -25 are 9 A motor contactors, the NCH8-40 is 15 A at 230 V and the NCH8-63 is 20 A. Add an overload relay for motor duty.
• Contacts: 2P versions come as 1NO, 1NC, 2NO, 2NC or 1NO+1NC. 4P versions come as 4NO, 4NC, 3NO+1NC or 2NO+2NC, depending on frame.
• Coil voltage: 24, 110, 120, 220/230 or 240 V AC. The coil voltage is part of the order code.
• Temperature: the 20 A unit carries 20 A at 40 degC, 18 A at 50, 16 A at 60 and 14 A at 70, so derate in a hot board.
• Standards and protection: IEC/EN 61095 and IEC 60947-4-1, rated insulation voltage 500 V and protection degree IP20.

Installing the NCH8

Snap the contactor onto the DIN rail, connect the load terminals and wire the coil to the control supply. Keep the rated insulation and IP20 protection in mind: the contactor must sit inside a closed enclosure or board. Leave space for heat to escape because several contactors side by side in a small board raise the temperature, and the heating-current table above shows how much capacity is lost. The electrical life figures in the catalog are 6,000 cycles for AC-1 and 30,000 cycles for AC-7a and AC-3/AC-7b, so frequent switching duties should be checked against these numbers.

Requesting a quotation for the CHINT NCH8

Send the rated current, contact arrangement, coil voltage, load type and quantity, with the order code such as NCH8-20/01 220/230V. Seven Star LLC will reply with a quotation and will suggest a different contactor if the load needs it.

NCH8 order codes and related contactors

The NCH8 order code identifies the current rating, contact arrangement and coil voltage in one string, for example NCH8-20/01 220/230V with the code 256245. Quote the exact order code so that the correct unit is supplied and the coil voltage is not mistaken. A 20 A unit is suitable for a bank of 20 tungsten lamps of 60 W each, which is a useful check for lighting circuits. The CHINT catalog is attached to this page and lists the full range, with dimensions and the electrical life figures.

For larger industrial motor starters compare the Schneider TeSys D LC1D and the ABB AF09 contactors, or browse the contactors and overload relays category on this site. Seven Star LLC can help you compare the ratings before you order.

Documents and quotation

The CHINT NCH8 catalog is attached and is the source of the table above. Send the full designation and quantity through the quotation form for availability from Seven Star LLC.