Module 10 Appliance Burner Pressures and Gas Rates Flashcards

1
Q

In plain English what does Regulation 29 say?

A

Do anything to an appliance measure operating pressure and/or gas rate

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2
Q

Which module covers burner pressure?

A

Module 10

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3
Q

Which module covers gas rates?

A

Module 10

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4
Q

Under Regulation 29 what must happen to the instructions for a new appliance:

a) Installer keeps them
b) Installer gives them to responsible person
c) They get thrown away

A

b) Installer gives them to responsible person

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5
Q

Name two places that you can find the burner pressure for an appliance

A

1) MI
2) Data plate

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6
Q

Attached image of a data plate

1) what is the mid range burner pressure?
2) Measured when the appliance is hot or cold?

A

1) 9.9 mbar
2) Hot

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7
Q

If the burner pressure cannot be found / obtained then you cannot comply with regulation 29. What should you do?

A

1) Poor performance = ID
2) Performance OK but can’t be checked = sub standard, deal with it! (NCS or AR)

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8
Q

Where is the burner pressure test point usually located?

A

On outlet side of multi-functional valve

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9
Q

The pressure test point located on the supply side of a multi-functional valve measures what?

A

Appliance supply pressure – should be circa 20 mbar

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10
Q

If the burner pressure is wrong and an appliance cannot be adjusted what can you assume and test?

A

Issue with supply pressure

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11
Q

Likely causes of excessive burner pressure

A

1) Faulty meter governor. Check working pressure at meter
2) If meter governor is faulty turn off gas supply and contact ESP

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12
Q

Why is excessive burner pressure an issue?

A

a) Incomplete combustion
b) Appliance overheating
c) Flue system unable to deal with extra products of combustion

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13
Q

Likely causes for low burner pressure

A

a) Faulty meter governor
b) Pipe sizing too small – test by turning more appliances on and see if pressure drops
c) Partial blockage of pipe work – check pressure at each appliance and work out if common pipe or individual
d) Damaged pipework - trace and repair

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14
Q

Describe what a range rate appliance is and how it should be set up.

A

Output of appliance adjusted to suit heating demand.
Set by adjusting burner pressure
Pressure falls outside of range – issue!

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15
Q

Where would you find a modulating burner?

A

Combination boiler – water full gas rate, heating range rated.

Often burner pressure not adjustable!

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16
Q

What is the link between the gas rate and the burner pressure?

A

Gas rate is determined by the calorific value of the gas, burner pressure and size of the injector

17
Q

Why measure gas rate?

A

Burner pressure won’t tell you if the appliance has the correct heat input. Why? Big injector, more gas, small injector, less gas, both same burner pressure!

18
Q

MI / Data badges usually do not contain gas rates. What other piece of information can we use instead?

A

Rated input (kW)

19
Q

How do you measure gas rate on a U6 type meter?

A

Time one complete revolution of the meter test dial

3600/secs for 1 revolution x 0.028 (converts it to metric) = m3/hr

(m3/hr x 38.6)/3.6 = Gross kW

Gross kW/1.1 = net kW

20
Q

How do you measure gas rate on a G4 meter?

A

Note meter reading, run appliance for two minutes, take second reading.

The maths:

(R2-R1) x 30 = m3/hr

(m3/hr x 38.6)/3.6 = Gross kW

Gross kW/1.1 = net kW

21
Q

An E6 meter has an LCD with three sets of units. Which set is used to measure gas rates?

A

The middle set
The first set is used for billing
The last number (6) is the rated meter capacity

22
Q

How do you convert kW to BTUs?

a) kW x 38.6
b) kW x 3,412
c) kW x 3,600

A

b) kW x 3,412

23
Q

What is a BTU?

A

British Thermal Unit

24
Q

How to do you calculate Heat input?

A

Gas Rate x Calorific Vale = MJ/hr

25
Q

Heat Input is calcluated in MJ/hr

The bolier is rated in kW

How do you convert from one to the other?

A

MJ/hr / 3.6

26
Q

A domestic gas fire - the meter takes 3 minutes to pass one cubic foot. What is the gas rate for this appliance?

A

3600 / 180 = 20

20 x 0.028 = 0.56m3/hr

27
Q

Gas rate using a G4 meter

Reading 1 (R1) = 00796.425

Reading 2 (R2) = 00796.476

What is the gas rate:

a) 1.53m3/hr
b) 59.05m3/hr
c) 16.41m3/hr
d) 14.91m3/hr

A

a) 1.53m3/hr

Why?

R2 - R1 = 0.051m3 per 2 minutes

Therefore 0.051m3 x 30 = 1.53m3 per hour

28
Q

If the gas rate is 0.56m3/hr what is the heat input for the appliance?

A
29
Q

A boiler is turned on and the meter test dial takes 45 seconds to pass 1ft3. What is the heat input in kW?

a) 2.24kW
b) 86.46kW
c) 24.02kW
d) 21.83kW

A

a) 2.24kW

30
Q

The gas rate test determines the gas volume being burned at the appliance burner.

True of False?

A

True

31
Q

U6 meter - one revolution of the dial = what volume?

A

1ft3

32
Q

Gas Rates

Hwo long should you leave an appliance on for to warm up?

a) 5 minutes
b) 10 minutes
c) 15 minutes
d) Any of the above

A

b) 10 minutes

33
Q

What type of meter is shown in the picture?

A

G4

34
Q

If the gas rate is out vs the data plate how do you determine whether you are over or under-gassed?

(E6 & G4 meters)

A

3600 = seconds in 1hr

m3 = volume of gas

10.76 = factor for natural gas

n = number of seconds until next digit apprears

35
Q

What is being measured at each point

A