Static Test; Magnet Coil Check - ABB 3000 Series Instruction Manual

1. If improper meter operation is suspected, proceed as follows:
a) Remove access covers from the junction box and the flowmeter housing.
b) Inspect for evidence of water entry in junction box and flowmeter housing.
If water entry is present, de-energize system at power source. Inspect conduit seals and cover
gaskets for possible source of water entry. Replace the seals and/or gaskets if evidence of water
entry is indicated. Allow interior of junction box and housing to dry completely before restoring
system power.
Since operating procedures are dependent upon the type of signal converter selected, the user
should refer to the instruction manual supplied with the signal converter for system troubleshooting
procedures. A static performance test for the flowmeter is discussed in Section 6.3.
2. Possible causes of erroneous flow rate indication are:
• incorrect grounding
• excessive noise due to a heavy slurry process
or a non-homogeneous process
• loose or intermittent wiring
• non-full or empty meter pipe
• excess air entrained in process liquid

6.3 Static Test

If improper operation of the flowmeter is suspected, the following resistance measurements can be
made to establish whether an electrical malfunction has occurred. A standard multimeter is suitable
for making the resistance checks. These measurements can be made at the flowmeter board located
in the base of the electronics housing.
ELECTRICAL SHOCK HAZARD. Equipment that operates from ac line
voltage constitutes a potential electric shock hazard to the user. Make
certain that the system power is disconnected before making the

6.3.1 Magnet Coil Check

14 through 24 inch meters have two magnet coils in the meter that are connected in series. The coil
leads are connected to terminals M1, CT and MR on the pc board in the flowmeter electronics base.
Before making resistance measurements, verify that the system power service has been de-ener-
gized. Remove the flowmeter electronics housing cover to obtain access to the flowmeter pc board.
1. Set the ohmmeter to its lowest range; e.g., R x 1.
2. Connect the ohmmeter test leads to terminal lugs M1 and CT. The value displayed
should correspond to 1/2 of the value ( ± 20%) indicated in Table 6-1.
6-2
10DS3111A INSTRUCTION MANUAL
WARNING
following ohmmeter checks.