Furnace Start-Up Flashcards
What is considered to be safe practice when inspecting electrical connections?
To make sure the power is turned off
A typical circuit board on any furnace will have only one voltage. True or False?
False
What should be checked on the blower assembly when performing the start-up?
Confirm that all the shipping blocks or brackets have been removed, make sure the wheel inside the housing is running in the center of it and that it is secured properly
What are three acceptable methods to check for gas leaks?
Test dial, commercial leak detector, and electronic leak detector
Which direction must the venting on the furnace slope?
Upwards and away from the furnace
What is the maximum distance the supports can be apart on system 636 venting?
Five feet
What should you be looking for when checking duct connections?
You should look for openings and gaps that might cause excessive leaking.
What should the heat anticipator setting match?
The amperage draw of the 24-volt circuit.
What are the reasons for setting the manifold pressure?
To ensure that the appliance is not overfiring and can be used to de-rate the appliance as well.
What is the formula for converting gas quantity into Btuh?
Btuh = Hourly Consumption x Calorific Value of the Gas
What is the calorific value for natural gas?
1000/ft3
What is the calorific value for propane gas?
2500/ft3
How is temperature rise calculated?
The difference of return air temperature and the supply air temperature.
When do the blower speeds have to be changed?
If the temperature rise is too low or too high
What is the first thing that you as an installer, must do when performing any system start-up?
Turn off the power supply
A furnace must be wired electrically and grounded in accordance to which codes?
National Electrical Code (NEC), ANSI/NSPA 70–2005 in the US, or the Canadian Electrical Code (CEC), CSA C22.1 in Canada
The power supply to the furnace connections must be between?
104 VAC and 127 VAC
Field wire connections must be made?
Inside the furnace connection box
What is one of the most important and easiest things to do on your checklist when installing a furnace?
Checking for gas leaks
What should you never do when looking for leaks in a gas line?
Never use an open flame
What kind of solution can be used to detect leaks?
A non-corrosive soapy water
What must be done if a leak is detected?
All leaks must be repaired, regardless of their size.
In the event of carbon monoxide leaking that causes illness, or is held responsible?
The individual that performs the start-up will be held liable.
What is vital for the safe operation of any gas appliance?
Venting the products of combustion
All venting systems must match the category of furnace for which it is intended. True or False?
True
All metal and vent connections must be?
ULC approved and have the ULC marking clearly indicated on the vent pipe.
The installation of all metal venting must adhere to the?
B149 gas code
Each change in direction adds?
10 feet
The installation of all plastic venting must be certified to the?
ULC S636 standard and must be clearly marked on all vent pipe and fittings.
What should you only be concerned with inspecting when only replacing a furnace?
The ducting in the furnace room only
What should you be concerned with inspecting on new construction?
The entire HVAC system
What is vital to do every time you install a new furnace?
That you fill out and complete a furnace start-up sheet
Thermostats can be either of which two types?
The mechanical or digital type
Which inlet side of the gas valve always has gas pressure coming out of it?
The inlet side
What should you always remember to do before connecting the manometer?
Turn off the gas at the shut off valve
Which side of the gas valve do you connect the manometer to check the supply gas pressure?
The inlet side
What is CH4?
Gas
What is C3H8?
Propane
The input rating of natural gas or propane must be decreased ___ for each 1000 ft above sea level.
4 percent
Who should and is qualified to do the high altitude gas conversion?
You
The Btuh value must not be equal or higher than the input rating for the appliance. True or False?
True
How many seconds are in an hour?
3600
On a two-stage gas valve, you need to set the pressure on how many stages?
On both stages
The temperature readings needed for calculating temperature rise are taken at?
The supply air plenum
The return air temperature can be taken anywhere in the?
Return air drop
What must do to the fan speed when the temperature rise is too low?
Decrease the fan speed
What must do to the fan speed when the temperature rise is too high?
Increase the fan speed
All motors used on residential furnaces are ___ VAC and are usually of the permanent split capacitor type
120 VAC
Low speed is used for?
Continuous fan operation
Medium speed is used for?
Heating mode
High speed is used for?
Cooling
What is a park terminal?
A terminal that is never energized on the board.
Testing the high limit is done by?
Simply removing the motor lead from the heating terminal and placing it on a park terminal.
The most common reason for changing on/off delays in mid or high efficient furnaces is for?
Comfort
