Contact Resistance Test

LKHPD > News > Articles > Contact Resistance Test


Electronic devices are ubiquitous nowadays, whether in residential or infrastructure environments. To prevent electrical damage, circuit breakers, switches, relays, and other electrical connections work 24/7.

However, as long as two conductors are in contact, you can expect some resistance. And too much resistance leads to power outages and other electrical emergencies. So regular maintenance is a must for these electrical connections. That’s where a contact resistance test comes in.

What is a contact resistance test?

The electrical contact resistance test (also known as Ductor testing) measures the resistance of electrical connections – terminations, joints, connectors, busbar sections or cable connections and so on. It measures either the voltage drop or the resistance offered by the contacts or resistance of the joints or connections.

The test measures the resistance at the micro- or milli-ohm level and is used primarily to verify that electrical connections are made properly. In the case of connections and joints of current-carrying parts, the test can:

  • Identify loose connectors
  • Show areas of high-voltage drop in the system
  • Indicate low tightness in bolted joints
  • Indicate corroded surfaces
Contact Resistant Test for branch cable

Why do you need contact resistance test?

The contacts in the circuit breaker needs to checked periodically to ensure that the breaker is healthy and functional. Poorly maintained or damaged contacts can cause arcing, loosing phase, and even fire. 

This contact resistance test is especially important for contacts that carry large amounts of current (e.g. switchgear busbars) because higher contact resistance can lead to lower current carrying capacity and higher losses.

Measurement of the contact resistance helps in identification of fretting corrosion of contacts, and allows contact corrosion to be diagnosed and prevented.

Contact corrosion leads to:

  • Power loss
  • Heat generation
  • Loss of contactor capacity
  • Failure to interrupt current when required

These problems can lead to major failure. Fretting corrosion at high temperatures is one of the causes of contact failure resulting in high contact resistance. Different surface coatings and other treatments are used to improve corrosion resistance of contact surfaces and contact tips.

Contact resistance tests for our branch cable & busway

At LKHPD, we provide contact resistance tests for branch cable and busway which helps to provide assurance for our customers.

Branch Cable 1


Branch Cable System (a.k.a Prefabricated Cables) That You Can Trust

With the rising cost in construction, increasing building complexity and tighter project deadlines, there is a growing need for a cost-effective, reliable and efficient solution. With our Branch Cable System, we pre-moulded our unique joint with the main and branch cable together in our factory so that it can be installed with ease and convenience at site.

Learn more

Busbar Trunking System


Low Voltage Busway – Low-Medium Voltage Cast Resin Busway – High Tension Busway

LKHPD is exclusive distributor of Schneider I Line II Busway System in Singapore

Our dedicated local project team is able to support our customers in the designing and drafting of the layout from ground up, installation, testing, and commissioning. Our busway supports applications that range from low voltage to high voltage up to 128KV which is well suited for Infrastructure, Data Centre, and any Building Construction Projects.

Learn more

5/5 - (1 vote)
Get a Quote