Instruction manual

NGA 2000 MLT Hardware
TEST PROCEDURE / TEST POINTS
11 - 6
Emerson Process Management GmbH & Co. OHG
Instruction Manual
90002929
07/2006
Fig. 11-4: PCB "BHZ” (position of signal LED's / heating transistors)
(heating transistor 3)
LED “red”
LED “red”
(heating transistor 4)
(heating transistor 1) (heating transistor 2)
LED “red”
LED “red”
Control LED “green”
11.2 Heating Unit
Test point: PCB “BHZ” (Fig. 11.4) of heater unit (Fig. 1-21. 1-24 and 1-27)
Measuring instrument: optical
Signal: red LED's of heater transistors must be off
green control LED must be blinking
Failure: red LED is on / green LED is out
Possible reason: Heater transistor defective (exchange PCB “BHZ”)
Check voltage supply of BHZ
Check “all internal connections” → PCB “BHZ”
HEATING UNIT