Fluid Components International GF90_GF92 - Manual (Page 73)

Doc. No. 06EN003229 Rev. H 69 GF Series Flow Meter Models GF90/GF92
FLUID COMPONENTS INTERNATIONAL LLC http://www.fluidcomponents.com
TERMINAL
NUMBER
APPROXIMATE
RESISTANCE
1 to 4 220 Ohms
2 to 4 0 Ohms
3 to 4 1000 Ohms*
5 to 4 1000 Ohms*
If the measured resistances correspond to Table 10 then the flow element is functioning properly. The
problem lies else where. Skip the rest of this section and proceed with the section, In-Depth
Troubleshooting - The flow transmitter. If the measured values do not correspond to Table 10 then a
problem exists in the flow element. For remote instruments, with a cable between the flow element and
the flow transmitter, the cable could be shorted or open. To isolate a problem with the cable, check the
flow element resistances at the terminal block located within the flow element (local) enclosure.
Disconnect the wires from the terminal block and measure resistances described below by touching the
DMM test leads to the terminal block screws. The measured resistances should correspond
approximately to the values in Table 11.
If the measured resistances correspond to Table 11 then the cable or wiring is defective. If the measured
values do not correspond to Table 11 then the Flow Element is defective. Contact customer service for
details on how to obtain another cable or flow element.
*For GF90HT divide by 10.
Table 11.
Resistance at Flow Element
Enclosure Terminal Block
Figure 36.
Flow Element Enclosure Terminal Block
In-Depth
Troubleshooting
GF90 with
VeriCal
The Flow
Element
Check Serial Numbers
Verify that the serial number of the flow element and the flow transmitter are the same. The flow element
and the flow transmitter are a matched set and cannot be operated independently of each other. The
only exception is when the flow transmitter has been specifically configured to be a replacement.
Check the Resistance of the Flow Element
Use Table 13 to determine if the flow element is wired incorrectly or has failed. Turn off the input power
to the transmitter. Unplug the flow element at JP3 located on the lower board and measure resistances
described below by touching the DMM test leads to the JP3 terminal screws. Plug JP3 is shown in
Figure 55. The numbers in Figure 55 have been added to the wire designations for discussion purposes
and are not found on the JP3 terminal plug or wires. (Remember to reconnect JP3 back to the flow
transmitter when finished.)
NOTE: If the system does not allow the disconnection of the flowmeter power, or unplugging the
flow element, then proceed to the section, "In-Depth Troubleshooting - The Flow
Transmitter".
All resistances in Table 13 are based on a temperature of 32°F (0 °C). Resistances across the ACT and
the REF RTDs for a GF90/92 are approximately 1080 ohms* and for a GF90 high temperature are
approximately 110 ohms* at 70 °F ( 21 °C ). The resistances will continue to increase for higher
temperatures at the flow element. Check resistance from each pin in the local/remote enclosure to case
ground. There should be an infinite resistance.