CSN HVAC Excellence: Electrical

The synchronous speed of a four pole 60 Hz single phase motor is

1800 RPM

The voltage to ground of a "high leg" or "stinger leg" on a three phase open Delta system will be around

208

replays are generally used to control inductive loads up to ___ amps

25

What is the minimum number of wires required between two Start/Stop push button controls

3

Acceptable temporary replacement for a run capacitor rated at 35MFD at 440VAC

37.5MFD at 440VAC

Resistance can be calculated by

E divided by I

What motor is the most energy efficient

ECM

Voltage can be calculated by

I x R

An ohmmeter should never be connected to

a charged capacitor until it has been discharged

When troubleshooting the A/C system in the schematic, the following conditions are found. The thermostat contacts are closed. The compressor and condenser fan are not running. The blower motor running. This could be caused by:

a faulty blower motor/blower relay

Contactor are rated according to the max amperage through the

contacts

Which of the following would be considered an inductive load?

electric motor

A device with overload protection used to control a motor is a

line starter

The thermal overload contacts on a line starter are usually ____ reset

manual

The ____ drawing illustrates were the components are located in small appliances

pictorial

If contacts become badly pitted, it is acceptable to

replace the contacts or control

Excessive current can be caused by

short circuit

When troubleshooting the A/C system in the schematic, the following conditions are found. The thermostat contacts are closed. The compressor and condenser fan are not running. The blower motor is running. This could be caused by:

the HP, LP, overloads, or oil pressure switch are open

To discharge a capacitor prior to ohmmeter testing

use a 15k/20k ohm, 2 to 5 watt resistor across the terminals