Merchanical Interlocking Contactor

About the Merchanical Interlocking Contactor

The Merchanical Interlocking Contactor is part of the ELEHPD AC Contactor range. Merchanical Interlocking Contactor from the ELEHPD AC Contactor range. ELEHPD manufactures and exports low voltage electrical products from Yueqing, Zhejiang, China, supplying distributors, panel builders, M&E contractors and OEM buyers worldwide.

Typical applications

Consumer units and distribution boards in residential buildings
Commercial and retail fit-outs where selective protection is required
Industrial control panels and machine-builder assemblies
Solar PV, EV charger and battery-storage sub-circuits
OEM equipment where a DIN-rail protective device is specified

How to specify the right AC Contactor

Match the rated current to the circuit design current, then check the cable ampacity
Pick the trip curve to the load: B for resistive/lighting, C for general mixed loads, D for motors and transformers
Confirm the breaking capacity meets the prospective short-circuit current at the point of installation
Verify the pole configuration (1P, 1P+N, 2P, 3P, 3P+N, 4P) against the system earthing arrangement

Specifications

Merchanical Interlocking Contactor 3TD series

SPECIFICATION

Type	Rated thermal current(A)	Rated operation current(A)	Controllable power of motor(KW)
AC-3	AC-4
380V	660V	380V	660V	380V	660V
3TD40	20	9	7	4	5.5	1.4	2.4
3TD41	20	12	8.5	5.5	7.5	1.9	3.3
3TD42	30	16	12.5	7.5	11	3.5	6
3TD43	30	22	16.5	10	15	4	6.6
3TD44	55	32	24	15	22	7.5	13
3TD45	55	38	24	18.5	22	9	15.5
3TD46	80	45	40	22	37	12	20.8
3TD47	80	63	60	30	55	14	24.3
3TD48	100	75	60	37	55	17	29.5
3TD49	100	85	80	45	75	21	36
3TD50	160	110	95	55	90	27	46.9
3TD51	160	140	120	75	110	35	60
3TD52	200	170	160	90	150	38	66
3TD53	210	205	165	110	160	50	86
3TD54	300	250	230	132	220	58	100
3TD55	300	300	260	160	250	66	114

Frequently asked questions about the Merchanical Interlocking Contactor

What is the difference between an MCB and an MCCB?

An MCB (miniature circuit breaker) is a DIN-rail device for final circuits, typically rated up to 125 A with a fixed trip curve. An MCCB (moulded case circuit breaker) is a larger device for main and sub-main distribution, usually 16 A to 1600 A, with adjustable thermal and magnetic settings and a higher breaking capacity. Use an MCB for branch circuits and an MCCB where you need adjustability or higher fault ratings.

How do I choose between a Type B, C and D trip curve?

Type B trips between 3 and 5 times rated current and suits resistive loads such as lighting and heaters. Type C trips between 5 and 10 times and is the general-purpose choice for socket circuits and mixed loads. Type D trips between 10 and 20 times and is used for loads with high inrush, such as motors, transformers and large LED drivers.

What does 6 kA breaking capacity mean in practice?

It is the maximum prospective short-circuit current the device can safely interrupt. 6 kA covers most domestic and light commercial installations. Where the transformer is close and the fault level is higher, specify 10 kA devices so the breaker still clears the fault without damage.

Can these devices be supplied with your own brand?

Yes. OEM branding, buyer-specific labels, custom carton print and private-model numbering can be arranged on qualified order volumes.