Dc resistance check, Dc voltage and current checks – Cleveland Motion Controls ULTRA SERIES CARTRIDGE TRANSDUCER REV AA User Manual

Page 18

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U

LTRA

S

ERIES

S

TATIONARY

S

HAFT

T

RANSDUCER

MAN-70251

R

EV

.

AA


P

AGE

18

OF

18

4.1.1 DC

R

ESISTANCE

C

HECK

If you have attempted to resolve your issue using the table above and have been unsuccessful, use the following
checks to determine the viability of the transducer.

The following nominal DC resistances table indicates a normal load cell, with no load applied at room temperature.
The resistances are cited using both the wire color and the M12 connector pin numbers (Figure 8). Often, it is best
to begin by measuring the resistances at the amplifier end of the cable. Then, if a problem is indicated, un-mate the
transducer end of the connector and check the resistances. Following this procedure, allows you to readily and
initially check the resistances without disturbing the transducer or M12 connections and inadvertently disturbing the
interconnect condition.

Measurements taken between the
following wires:

Corresponding M12 Connector Pins:

Target Resistance

WHT - BLK

2-4

118 Ohm

BRN - BLU

1-3

140 Ohm
Varies slightly based on load cell
temperature

WHT - BLU

2-3

112 Ohm

WHT - BRN

2-1

88 Ohm

BLK - BRN

4-1

88 Ohm

Resistance should NOT be indicated (> 10 M-ohm) between any of the transducer connections and the metal body
of the transducer when the M12 transducer connector is un-mated. A low resistance indicates a possible breakdown
of an insulation component, and could be caused by excessive voltage between the body and electrical connections
of the transducer.

4.1.2 DC

V

OLTAGE AND

C

URRENT

C

HECKS

When 5VDC excitation is applied to a correctly wired transducer, the output to ground voltage for each of the bridge
outputs should be approximately 2.8 VDC. The difference in voltage between the two output leads (BLK and
WHT) is the un-amplified tension signal. It should be only tens of millivolts with little applied force, increasing to
approximately 350 mV at the transducers MWF.

The current flow through the bridge Excitation connections (into BRN and out the BLU wire) should be
approximately 35 mA and equal in each wire. Non-equal currents indicate that the current is being diverted,
indicating a potential wiring error, short circuit, or ground loop.

Trademark Information
Kidder is a registered trademark of Cleveland Motion Controls.

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