Buying guides
Plain answers to the questions customers ask us most: which MCB, which starter, which cable, which MPCB, how much capacitor and more.
- Guide
Which MCB do I need? Rating, curve and poles explained
How to pick the MCB rating, trip curve and number of poles for lights, sockets, ACs, geysers and three-phase circuits.
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DOL or star-delta starter: which one for your motor?
The difference between direct-on-line and star-delta starters, when to use each, and how to set the overload relay.
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How to choose an MPCB rating for your motor
A motor protection circuit breaker protects against short circuit, overload and phase loss in one unit. Here is how to pick its range.
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How to size a capacitor for power factor correction
Work out the kVAr needed to raise your power factor, then choose between fixed capacitors and an APFC panel, and the right duty and voltage.
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MCB, RCCB, MCCB and MPCB: what is the difference?
What each protective device does, its usual current range, and where it is used in a panel or distribution board.
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Which cable size for a submersible pump?
The cable must carry the motor current and keep the voltage drop low over the full length down the borewell.
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Why does my MCB or RCCB keep tripping?
A tripping breaker is doing its job. Here is how to find out why it trips, and when the breaker itself needs replacing.
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Single phasing: why motors and pumps burn, and how to prevent it
Losing one of the three phases is the most common reason pump motors burn. A single phasing preventer switches the motor off before it is damaged.
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Which wire size for home wiring?
Choosing the right sq mm for each circuit, the MCB that goes with it, and the colour code to follow.
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Armoured vs unarmoured cable: which one do you need?
How armour protects a cable, where it is needed, and the other choices to make: conductor, insulation, cores and size.
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How to choose an MCCB
Four decisions make the right MCCB: the current rating, the breaking capacity, the number of poles and the type of release.
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Capacitor duty contactor vs normal contactor
Switching a capacitor is very different from switching a motor. That is why APFC panels use special capacitor duty contactors.
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Generator changeover: manual, on-load or automatic?
A changeover switch connects your load to either the mains or the generator, never both. Here is how to choose the right type and size.
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How to read a motor nameplate
The nameplate tells you everything needed to choose the starter, MPCB, relay and cable. Here is what each field means.
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L&T switchgear is now Lauritz Knudsen: what changed?
If you have bought L&T MCBs, contactors or starters for years, here is what the new Lauritz Knudsen name means for you.
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