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The main circuit board in your furnace sends a small ac signal to the flame rod so now you have an ac potential from the body of the furnace to the flame rod, When the flame comes on between the body of the furnace and the rod it rectifies the ac in to dc, The flame actually acts like a diode. When this dc voltage is sensed by the control board it knows there is a flame present and thus keeps the gas valve on.

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What is flame rectification?

Flame rectification is DC electrical circuit that sends a very small voltage (rated in micro amps) from the furnace electronic board up through the pilot electrode. When pilot flame is established the flame acts as a path (conductor) which allows the DC current to flow from the flame rod to ground completing the circuit. This completed signal tells the electronic board it's ok to allow the main gas valve to open . Now your furnace pilot, or hot surface ignitor will start the main flame . To put it simple, flame rectification is an electronic way to prove pilot flame before opening the main burner gas valve. It's a safety circuit to prevent the main burner gas valve from opening if there isn't apilot flame, or hot surface ignitor established.


How does a motor run?

the north pole magnet and straight rod present in the moter .the current flow in the rod and rod rotate on the magnetic force.And the moter run.


Is a 6 foot grounding rod long enough for a new panel?

Code states that a grounding rod needs to be 8 feet long. A 6 foot rod should be okay in theory, but 8' is code.


How many grounding clamps are permitted on one ground rod?

As long as the clamp is of an approved type only one is needed per ground rod.


Can a down rod be installed on a flush mount ceiling fan?

I would say yes because I've never seen a ceiling fan that couldn't be installed on a down rod. In fact, I've never personally seen a ceiling fan that couldn't be installed either way. You can use a down rod of any length, at your discretion. You can buy rods of various lengths or have one cut to the length you want. Beyond a few inches, maybe a foot, you will have to install additional wires to allow for length of the rod.

Related Questions

How do you check a flame rod?

To check a flame rod, disconnect it from the control circuit and use a multimeter set to read resistance in ohms. Insert one probe into the terminal of the flame rod and the other probe to the metal rod itself. A good flame rod will typically have a resistance reading between 3 to 30 ohms. If the flame rod shows no continuity or a significantly high resistance, it may need to be cleaned or replaced.


Why is a yellow flame observed when glass rod heated?

The yellow flame observed when heating a glass rod is due to the presence of impurities on the surface of the rod, such as residual organic materials or contaminants. When these impurities are heated, they undergo combustion and emit a yellow-colored flame. Heating the glass rod to a higher temperature can help burn off these impurities and restore a clear flame.


Can a flame rod burn out?

A flame rod is a simple piece of heat-resistant metal (nichrome, inconel, etc) in contact with a flame. A flame consists of ionized particles undergoing chemical reactions and therefore is conductive. The flame rod takes advantage of that fact. The rod has a small potential on it and when the flame touches it, a small current flows from the rod through the flame to ground. This current is detected and uses to "prove" the flame. A flame acts as a diode but I don't recall the direction of electron flow and that effect isn't used in this application. The rod's response is instantaneous. That, and there being nothing to degrade, are the two main benefits. The major detraction is that active, powered electronics are needed to process the signal. All pilotless gas systems use flame rods. If the ignition system is by spark then the flame rod and the ignition rod may be the same. Other systems use separate spark and flame rods. Yet other ignition systems such as the hot body ignitor don't involve the use of sparks at all. A similar application is the pilot light sustainer. This little gadget detects when the pilot light goes out and sparks to relight it.


When you hold a metal rod over a flame the end of the rod away from the flame gets hot how does this happen?

Metals generally exhibit good thermal conductivity. When one end of the metal rod is held in the flame it absorbs thermal energy and becomes hot. Thermal energy is conducted quickly along the material (from hotter to cooler parts of the rod), and the other end eventually becomes hot. This principal is used in cooling systems for electronics (for example) with heat sinks drawing thermal energy away from hot components in order to radiate it elsewhere.


Why is heat conduction through a metal rod faster if the rod is pointed DOWN into a flame than when it is pointed UP into a flame?

Because heat travels "up." I disagree. Heat travels "up" in a fluid, because the molecules expand and become lighter and "float" upwards. But in a solid? How can that be? If you notice, the question is asking about a rod being pointed down into a FLAME versus up. As we all know, flames "point" up, not down. Therefore it is hottest at the tip of the flame. This should answer the question. If not...feel free to message me.


Where is the flame sensor located on my furnace?

The flame sensor on your furnace is typically located near the burner assembly, close to where the flame ignites. It is a small metal rod that detects the presence of a flame and signals the furnace to continue operating.


What color does the element Mg impart to the flame?

The flame test is not used to detect magnesium; a magnesium oxide rod is used as a support for the solutions of other elements in the flame test.


What does Abbie drive?

Abby drives a flame red 1931 Ford Coupe hot rod.


What is a ceramic rod?

A ceramic rod is in some heaters that glow red in the flame. It uses coal so like a radiator! thanks for asking this question! I know everything! :)


How does a flame sensor work in home furnaces by using a metal rod in the flame?

Its not a flamesensor its a pilot generater it generates a small amound of electricity to open the main valve that way if your pilot light goes out it wont let gas escape and couse a potentian explosion The above answer is not accurate unless you have a standing pilot model furnace. Then the "flame sensor is called a thermocouple, much different than the flame sensors used in Direct Spark Ignition, hot-surface and intermitant ignition furnaces. The flame sensor uses the flame of the main burner to prove flame at the circuit board by measuring conductivity to ground through the flame.


How far from the flame should one work?

One should work far enough away from the flame to avoid contact with the flame itself. A person should have enough distance from the flame to keep loose clothing and hair safe as well.


How does a rod work?

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