Views: 80 Author: Site Editor Publish Time: 2022-11-10 Origin: Site
Coffee, as the best drink during white-collar work time, it can not only refresh the mind, improve the mood, so as to relieve fatigue, improve work efficiency. The origin of coffee is unknown. Legend has it that coffee was discovered more than a thousand years ago by a shepherd who discovered that his sheep became very excited after eating a plant. It is also said that a wildfire destroyed a coffee forest, and the smell of barbecue coffee caught the attention of the surrounding residents... If you want a good cup of coffee, you need a quality coffee maker. How to inspect the coffee machine? What are the inspection standards and inspection methods of the coffee machine?
One: leakage current test
1: Test method: With a sample that has not been tested, through 120V / 60Hz power supply, under normal operation with leakage ammeter to measure, and record the test data as follows.
Test method To measure the maximum leakage current
The sample is not energized.
Power on for 0 to 5 seconds
5 seconds to 10 minutes
More than 10 minutes (reach the hot state)
Power off in hot state
2: The test result determines that the maximum leakage current cannot exceed 0.5mA
Two: input power test
1. Test method: Energize the sample and make it work under normal load. Record the following chart data
Test conditions V A W
Power on immediately read value 120
Read value 120 when working to hot state
Increase the voltage to the rated power
2: The result determines that the measured power is between 90% and 105% of the nominal power.
Three: operation test under normal conditions
1. Test method: Test sample under normal operation conditions (subject to the instruction manual), including cleaning, maintenance, etc.
2. Result judgment: Fire, electric shock and other dangers should not occur in the process of operation.
Four: normal temperature rise test
1. Test method: (4 temperature rise modes are required)
(1) a: Place the sample on the blackened board.
b: The voltage of the sample is 120V / 60Hz or reaches the rated power.
c: Before the test, the rubber pads of the sample should be removed if they can be removed.
d: Fill the coffee pot with graduated water and start to heat it, with all the hot water dripping into the cup as a cycle. I'm going to do five cycles,
e: The temperature rise test of the first mode has been completed.
(2) The test conditions remain the same. Do not remove the cup after the fifth cycle, and keep the amount of water in the cup until the temperature reaches equilibrium.
(3) The test conditions remain the same. After the fifth cycle, pour out the water until the temperature reaches equilibrium.
(4) The above test conditions remain the same. After the fifth cycle, remove the container until the temperature reaches equilibrium.
2: The result determines that the temperature of each point meets the safety standard. (See UL1082 Table33 for details. 1)
Five: high pressure test
1. Test method: In the hot state of the sample, paste the tin foil on the sample housing, power cord L, N, and apply 1000Vac high pressure to the housing surface wrapped in tin foil. The test time is 1 minute.
2: Results: High pressure can not be broken down.
Six: moisture test
1. Test method: Put the test sample in the constant temperature and humidity box, the temperature is set at 32℃ and the humidity is set at 88%. Take out the sample after 48 hours. Then repeat leakage current test and high voltage test.
2: The result judged that 1000Vac could not be broken down, and the maximum leakage current was less than 0.5mA.
Seven: power cord tension test
1. Test method: Cut the place where the power cord is connected to the PCB board with cutting pliers (when cutting the wire, pay attention to the copper wire and wire cover is flat), and then apply 156N weight to the power cord for 1 minute.
2: The result judged: the copper wire of the power cord should not be indented by more than 2mm, or the power cord should be pulled out.
Eight: power line thrust test
1: Test method: Apply a thrust at the outlet of the power cord 25.4mm until the wire is bent or the thrust exceeds 26.7N
2: Result judgment:
a: There is no mechanical damage to the power cord.
b: The copper cable of the power cable is not exposed.
c: There is no damage to internal components or wiring.
Nine: oven baking test
1: Test method: Put the sample in the oven, the oven temperature is set at 10℃ and the maximum temperature of the shell when the temperature rises, but the oven temperature can not be 70℃ at the bottom, then, 7 hours later, take out the sample, let the temperature drop to room temperature.
2: The result judged: the test sample did not shrink, melt,
Ten: power cord tension test (after the oven baking test.)
1. Test method: After the sample is baked in the oven, the sample is cooled to room temperature and the power cord tension test is repeated. The measurement conditions and determination method are the same as the power cord tension test.
1:15 º Angle test
(1) Test method: Put the test sample on the surface of 15º Angle, then fill the sample container with water according to normal operation, and place the sample at different angles on the inclined surface.
(2) Results: The test sample should not be tipped or slid at any Angle.
2: Impact test
(1) Test method: Produced by a rubber ball (see UL1082Fig26.1)
0.75ft-1bf hit the product most likely to tip over. See Figure 28.2
(2) Result judgment:
If it is overturned, a) the lid cannot be moved b) the liquid flow rate is less than 133ml/S within 5 seconds,
If it does not tip over, the liquid outflow is less than 104ml/s
Xii: Impact test
1: Test method
Prepare three samples to be placed on a hard platform (magnetic floor is acceptable) and dropped from a height of 38cm (metal part) or 19cm (plastic part) using steel balls with diameter of 50.8mm and weight of 0.535kg. Each sample is struck once. High pressure after the test.
2: Result judgment: a: High pressure test passed. b: If the shell is damaged, the test finger should be used to detect it. The test finger should not touch the live body or live component.
Thirteen: Exception test
1: Overflow test
(1) Test method: Put the sample on the surface of normal operation, power the sample, add hard water to the capacity cup to the maximum scale, and then take a water cup to fill 50% of the capacity of the capacity cup, but not more than 470ml, with a 9.5mm diameter funnel filled with hard water, after filling, gently dry the shell with gauze. Connect a 500Ω resistor in series between the visible metal part and the power supply. Pass I = U/R to get the leakage current. Repeat the high voltage test.
(2) Result judgment: a) High pressure test must pass
b) The leakage current obtained from I = U/R is less than 5mA
Remarks: Hard water, that is, add 0.5 grams of calcium sulfate to 1 liter of water.
2: Dry burning test
(1) Test method: Short-circuit temperature controller, but Thermalcutoff such as temperature limiting device in action, then give the visible metal part with the power ground wire indirect a 3AUL approved fast fuse. Fill the cup with hard water and run the electricity until the final result appears. (This test is performed at the test corner),
(2) : Result judgment:
a: The shell has not caught fire or burned.
b: 3AFuse is not broken.
c: Replace 3AFuse with 500Ω resistance, measure the voltage at both ends of the 500Ω resistance, and calculate the leakage current is less than 5mA.
d: Repeat high pressure test, must pass.
14:50 times temperature controller overload test
1. Test method: Connect 120% of rated voltage or 120% of rated power to a 3AUL approved fast fuse sample indirectly between the visible metal part and the power ground wire (choose the higher voltage of the two), and make the thermostat operate 50 times, (10 times/min).
2: Result judgment:
a: 3AFuse cannot be broken.
b: The thermostat has no electrical or mechanical failures.
Fifteen: Blow fuse test
1: Test method: Short-circuit thermostat, but Thermalcutoff such as temperature limiting device in action, then give the visible metal part with the power ground wire indirect a 3AUL approved fast fuse. Fill the cup with hard water and run the electricity until the final result appears. (A total of 5 samples were tested at the test corner)
2: Result judgment:,
a: 3AFuse cannot be broken
b: The shell should not catch fire
c: Internal components must not be exposed.
d: The metal didn't melt.
e: The sample placement surface is in good condition.
Xvi: component damage test
1: Test method: Give a 3AUL approved fast fuse to the visible metal part indirectly connected to the power supply ground wire. And then power-on, in turn short circuit if failure will affect the safety of the capacitor, resistor, diode, transistor, etc.
2; Result judgment:
a: 3AFuse cannot be broken.
b: There is no flame coming out of the casing or the casing melting off.
c: Repeated high pressure test passed.
Seventeen: 100 Cycle test of the whole machine
1. Test method:
a: Three sets of samples were filled with 0.025% Nacl solution and heated and kept warm for 30 minutes for a total of 80 cycles.
b: Replace Nacl solution in a with water, brew coffee and keep it warm for 30 minutes for 20 cycles.
2: Result judgment: 100 cycles. After completion, the leakage current test, high voltage test and overflow test were repeated, and the results were determined to be the same as those described above.