R-24ST/R-2B34 - 13
6. Measure the final water temperature. (Example: The final temperature T2 = 21
°
C)
7. Calculate the microwave power output P in watts from above formula.
Initial temperature T1 = 11
°
C
Temperature after (52+ 3) = 55 sec. ............................................................................. T2 = 21
°
C
Temperature difference Cold-Warm ............................................................................
∆
T1 = 10
°
C
Measured output power
The equation is “P = 80 x
∆
T” ............................................................... P = 80 x 10
°
C = 800Watts
JUDGEMENT: The measured output power should be at least
±
15 % of the rated output power.
CAUTION: 1
°
C CORRESPONDS TO 80 WATTS. REPEAT MEASUREMENT IF THE POWER IS
INSUFFICIENT.
WARNING: High voltages and large currents are present at the secondary winding and
filament winding of the power transformer. It is very dangerous to work near
this part when the oven is on. NEVER make any voltage measurements of the
high-voltage circuits, including the magnetron filament.
Heat up for 55 sec.
B
POWER TRANSFORMER TEST
CARRY OUT 3D CHECKS
Disconnect the leads to the primary winding of the power transformer. Disconnect the filament and
secondary winding connections from the rest of the HV circuitry. Using an ohmmeter, set on a low range,
it is possible to check the continuity of all three windings. The following readings should be obtained:-
a. Primary winding ............ 2.3 ohms approximately
b. Secondary winding ....... 140 ohms approximately
c. Filament winding ........... less than 1 ohm
If the reading obtained are not as stated above, then the power transformer is probably faulty and should
be replaced.
CARRY OUT 4R CHECKS
TEST PROCEDURES
1000g
1000g
1000g
T1˚C
T2˚C
PROCEDURE
LETTER
COMPONENT TEST
