AVR 240 (serv.man13) - Harman Kardon Audio EMC - CB Certificate (repair manual). Page 32

 

 

- Page 27 of 33 - 

 

 

 

Report No.  65654 

 
 

Monitored point: 

 

 

dT (K)  

at 207V 

dT (K)  

at 253V 

Limit dT (K)

*) 

Main transformer core 

 

 

53,6 

57,5 

85 

Sub transformer core 

 

 

37,4 

45,0 

85 

Diode, D991 body 

 

 

61,5 

63,9 

- 

PWB near D991 

 

 

61,9 

63,0 

85 

TR, Q803 body 

 

 

50,5 

59,5 

- 

TR, Q804 body 

 

 

32,5 

38,9 

- 

PWB near Q804 

 

 

48,1 

56,0 

85 

E. Capacitor, C909 body 

 

 

33,4 

36,8 

- 

E. Capacitor, C916 body 

 

 

25,9 

29,0 

- 

Resistor, R810 body 

 

 

44,2 

50,3 

- 

Main heat-sink 

 

 

49,2 

59,3 

- 

Fan body (on heat-sink) 

 

 

31,8 

38,3 

60 

Power cord bushing 

 

 

26,6 

28,6 

60 

Top enclosure above main transformer 

 

 

30,3 

35,0 

65 **) 

Top enclosure above main heat-sink 

 

 

27,8 

33,5 

65 **) 

 

 

 

 

 

 

*) Temperature rise limits for Singapore is 10K less 

**) Directly covering part for heat-sink and transformer. The top cover is supplied with ventilation openings 
covering most of the top cover. This indicate emission of heat from internal parts and the opening area is 
therefore not likely to be touched during normal use. 

 

Winding temperature rise measurements

 207V 

253V 

— 

 

Ambient temperature t1 (

o

C) :

 24,5 

24,5 

— 

 

Ambient temperature t2 (

o

C) :

 24,9 

23,5 

— 

Temperature rise dT of winding: 

R

1

 (Ω) 

R

2

 (Ω) 

dT (K) 

Limit dT (K)  Insulation 

class 

Main transf. pr. winding (207V) 

1,807 2,288 68,5  85 

E 

Sub transf. pr. winding (207V) 

2747 3235 45,6  85 

E 

 

 

 

 

 

 

Main transf. pr. winding (253V) 

1,807 2,305 72,4  85 

E 

Sub transf. pr. winding (253V) 

2747 3347 57,6  85 

E 

         

         

         

TRF No:  IEC/EN 60065F