# What do the numbers on a contactor mean?

## What do the numbers on a contactor mean?

These auxiliary contacts (also called control contacts) each have an order number and a function number. The first number is used consecutively (order number) and the second number specifies the type of contact (function number).

What are the contactor categories?

There are different types of contacts in a contactor namely, contact springs, auxiliary contacts, and power contacts. Each type of contact has an individual role to play.

### How is contactor size calculated?

Making/Breaking Capacity of Contactor=1.5×13= 19 Amp. Size of Star Contactor (Starting Condition) = 33%X Full Load Current (Line). Size of Star Contactor =33%x13 = 4 Amp. Size of Main Contactor (Starting-Transition-Running) = 58%X Full Load Current (Line).

What is LRA on a contactor?

LRA (Locked Rotor Amperes): This is a locked rotor (starting) current of the motor (compressor). This is generally inductive load with power factor @ 0.5. Resistive Amperes: The current when the load is resistor. This is generally used for Electrical heating application. The power factor is @ 1.0.

#### What is 13 and 14 on a contactor?

Many contactor manufacturers use the designations A1 and A2 for the terminals that connect power to the magnetic coil. Likewise, many manufacturers use the designations 13 and 14 for the terminals of normally open auxiliary contacts. Auxiliary contacts are operated by the magnetic coil just like the main contacts.

What is ac15?

AC-15 may refer to: AC-15, the IEC Utilization categories indicating the type of electrical load. AC-15, one of the first guitar amplifiers designed by Vox. Autovía AC-15, a Spanish highway in the province of A Coruña, Galicia.

## How do I choose a contactor?

Power contactors have 3 poles or 4 poles versions. You should select the suitable contactor according to the number of phases of the load. For example, if you want to control a 3 phase motor, you should use 3 pole contactor. If you want to disconnect the neutral, your choice should be 4 pole version.

What is LRA and RLA?

LRA – Locked Rotor Amps: The current you can expect under starting conditions when you apply full voltage. It occurs instantly during start up. RLA – Rated Load Amps: The maximum current a compressor should draw under any operating conditions.

### What is the res rating on a contactor?

The RES rating is the RESISTIVE LOAD AMPACITY (amperage capacity) or rating. Remember, a contactor and relay is both a switch (contacts) and a load (coil) that controls the switch (contacts). The FLA, RES, and LRA are the ratings of the switch/contacts/points portion of the relay/contactor, not the coil portion.