Service, 2 sensor or drive coil fault – KROHNE MFC 400 EN User Manual
Page 117
SERVICE
7
117
MFC 400
www.krohne.com
08/2013 - 4002075802 - MA MFC 400 R02 en
7.2 Sensor or drive coil fault
The specified values are for guidance only.
Typical values for sensor or drive coils
Typical RTD resistances
• Resistance values outside of the ranges specified above may indicate a circuit error. The
device may be in "start-up" mode or indicate measuring errors.
• All circuits should be isolated with respect to earth (device housing) and each other >20 MΩ.
• A drive/sensor coil short circuit can cause the device to be put into "Startup mode".
Size
Resistance (Ohm)
Driver
Sensor A - Sensor B
black/grey
purple/green - white/yellow
Cryo 230°C /
446°F
400°C / 752°F
Cryo 230°C /
446°F
400°C / 752°F
6000 - 08
72
12
640
1455
6000 - 10
68
6
640
1455
6000 - 15
68
6
640
1455
6000 - 25
42
12
342
755
6000 - 50
42
52
342
755
6000 - 80
42
52
443
960
6000 - 100
42
54
342
755
6000 - 150
42
54
375
852
6000 - 200
42
54
375
852
6000 - 250
42
54
375
852
Resistance (Ohm)
Pt500
Compensation lines
red/brown
brown/orange
6000 - all sizes
540 at 20°C / 68°F
0.1
INFORMATION!
Failure of two or more of the upper circuits may indicate a measuring tube error. There may be
product in the housing. If this is the case, depressurise
depressurise
depressurise
depressurise the process line and immediately remove
the measuring device from the process line.
.book Page 117 Monday, August 26, 2013 9:05 AM