KROHNE MFC 300 EN - Manual (Page 125)

SERVICE
7
125
MFC 300
www.krohne.com 02/2012 - 4000498602 - MA MFC 300 R03 en
7.2 Driver or sensor coil fault
Typical inductance and resistance values
7.2.1 OPTIMASS 1000
The specified values are for guidance only.
• Driver = black and grey
• Sensor A = white and yellow
• Sensor B = green and violet
• Pt500 = red and blue (530…550 Ω) at ambient temperature
• Strain values measuring tube = 420...560 Ω
• 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.
• An exciter/sensor coil short circuit may cause the meter to be in "start-up" mode.
Size Resistance (Ohm)
Driver Sensor A/B
15 220 78
25 220 64
40 163 78
50 163 64
15-Ex 220 78
25-Ex 220 64
40-Ex 94 78
50-Ex 94 64
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 125 Monday, February 6, 2012 11:01 AM