277780

What type of electrical component is this?

This is a three-pole power contactor designed for switching motors and other industrial electrical loads. The 277780 uses a DC-operated coil and screw-terminal connections.

What control voltage does the contactor require?

The contactor requires a smoothed DC control voltage between 24 V and 27 V.

What is its motor rating at 400 V?

For AC-3 motor switching at 380–400 V, the contactor is rated at 40 A and up to 18.5 kW.

How many main contacts does it have?

It has three normally open main contacts, making it suitable for controlling three-phase loads.

Does it include auxiliary contacts?

No auxiliary contacts are built into the basic unit. Compatible auxiliary contact modules can be fitted when additional signalling or control contacts are required.

Which utilisation categories apply to this contactor?

It is rated for AC-1, AC-3, AC-3e and AC-4 applications. These categories cover resistive loads, standard motor starting and stopping, and demanding duties such as inching, plugging and reversing.

What is the AC-1 current rating?

The conventional free-air thermal current for three-pole AC-1 operation is 60 A at 40 °C. When enclosed, the stated thermal current is 45 A.

Can it be used for frequent motor switching?

Yes. The contactor is intended for industrial motor control, with a stated mechanical operating frequency of up to 5,000 operations per hour under the specified conditions.

What types of machinery commonly use this contactor?

Typical applications include pumps, compressors, fans, conveyor belts, mixers, lifts, escalators, centrifuges, agitators and general manufacturing machinery.

What connection method is used?

Both the main circuit and control circuit use screw terminals. The main terminals use M6 screws, while the control terminals use M3.5 screws.

What ambient temperatures can it operate in?

For open installation, the specified operating range is -25 °C to +60 °C. In an enclosure, the stated range is -25 °C to +40 °C.

What is the maximum operating altitude?

The specified maximum installation altitude is 2,000 metres above sea level.

What are the insulation and operating voltage ratings?

The rated insulation voltage is 690 V AC, the rated operational voltage is up to 690 V AC, and the rated impulse withstand voltage is 8 kV.

Is the contactor suitable for continuous energisation?

Yes. Its DC coil has a 100% duty factor, allowing continuous energisation when operated within the specified voltage and environmental limits.

Does the coil include interference suppression?

Yes. The actuating electronics incorporate a suppressor circuit to help limit electrical interference generated during coil switching.

What is the mechanical service life?

The specified mechanical lifespan is approximately 10 million operations for the DC-operated contactor under the stated test conditions.

What degree of ingress protection does the basic unit provide?

The basic contactor is rated IP00, so its final level of protection depends on installation within a suitably designed panel or enclosure.

Can it switch DC loads?

Yes. For DC-1 operation, the stated ratings are 50 A at 60 V DC, 50 A at 110 V DC and 45 A at 220 V DC, subject to the specified installation conditions.