HVAC/R Unit 67 Electric Heat Installation
A _______-Kilowatt electric furnace will use approximately ______ amps. A typical modern residential electric service connection is ______________ amps, while older houses have service connections of 60-100 amps. In some cases, the home's electric service connection may have to be __________ before an electric furnace can be installed.
20, 84; 150-200; Upgraded.
What is the ideal clearance for service?
36 Inches is the ideal amount of space for service.
What should be used to protect the furnace?
A circuit breaker no larger than the maximum over-current rating on the data plate.
Sometimes ___________ ____________ are used to save on installation cost, because large-guage copper wire can be expensive. Before _________ ________ can be considered for use, check the furnace manufacturer's warning label.
Aluminum Conductors; Aluminum Wiring
The __________ should be sized using the wire sizing tables of the National Electrical Code to handle the minimum circuit amperage rating listed on the unit data plate.
Conductor
After all heating elements are operating, measure the temperature of the air entering and leaving the furnace. The _____________ between these two temperatures is the _________ __________. The temperature rise should fall within the range listed in the furnace installation instructions. If the temperature rise is too high, the fan speed should be _____________. If the temperature rise is too low, the fan speed should be ____________.
Difference, Temperature Rise; Increased; Decreased.
Not all furnace's surfaces requires the same amount of clearance. The bottom of the furnace may rest ____________ on a plywood base with no clearance, but the front may require ________ inches or more for service.
Directly, 24.
There should be a ________ ________ located within sight of the furnace sized at 115% of the unit's minimum circuit ampacity.
Disconnect Switch.
What must be considered when selecting electric heat?
Electric Service Capacity.
Electric heat installation is ________ _________ to install than most other types of heating.
Less complicated.
If no guidance is given about aluminum conductors within the installation guide, what is the next step?
The installer must check to see if the connections on the furnace is designed for aluminum conductors. Usually represented as "Cu/Al"
What is the most important part of an electric furnace installation?
The sizing of the wire is the most important part of installation.
Why should Furnaces never be installed on bare ceiling joists?
The vibrations from the fan would cause loud noises to sound through the entire house. Therefore, they must by installed with shock pads to minimize vibrations.
During the start-up procedures when should you check the voltage to the furnace?
The voltage should be checked before and after starting the furnace.
True or False: All forms of electric heat use large amounts of current.
True
