Troubleshooting - GPI GM Serie Guía De Operaciónes

The. GPI. 4-20. mA. Transmitter. offers. a. choice. of. five.
response-time.settings,.selectable.by.the.unit's.push-
buttons.
Procedure
1.. Start.with.the.transmitter.unpowered..If.the.trans-
mitter.is.presently.operating,.temporarily.disable.its.
external.power.supply..Be.sure.to.allow.at.least.30.
seconds.to.elapse.with.unit.unpowered.
2.. Press.and.hold.the."4".button..While.holding,.watch.
the.indicator.light.and.power.up.the.transmitter.
3.. Shortly.after.power.is.applied,.the.light.will.blink.one.
or.more.times..Count.the.number.of.blinks.(from.1.
to.5.blinks).and.release.the.button.after.the.blinking.
has.finished.
NOTE:..If.necessary,.repeat.steps.1.through.3.to.get.
the.number.of.blinks.corresponding.to.the.response.
time.you.want.
. Blinks. ..
. 1.blink. .
. 2.blinks..
. 3.blinks..
. 4.blinks..
. 5.blinks..

TROUBLESHOOTING

SYMPTOM
A.. LOOP.OUTPUT."STUCK".AT.
. ZERO.(no.reading.at.all).
. .
REGARDLESS.OF.INPUT.
. .
SIGNAL
.
. .
B.. LOOP.OUTPUT."STUCK".
AT.LOW.VALUE.(Between.
. .
1.and.4.mA).REGARDLESS
.
OF.INPUT.SIGNAL
. .
. .
C.. LOOP.OUTPUT."STUCK".AT.
. ..
FULLSCALE.(above.20.ma)
. .
REGARDLESS.OF.INPUT
. .
SIGNAL
D.. LOOP.OUTPUT.WITHIN.
. NORMAL.RANGE,.BUT.
. INCORRECT
E.. LOOP.OUTPUT."BOUNCES". 1.. Output.response-time.setting.too.
. ERRATICALLY.(is.unstable).
.
. .
. .
F.. LOOP-OUTPUT.STABLE.BUT. 1.. Output.response-time.setting.too.
. RESPONSE.TIME.TOO.SLOW. .
G.. LOOP-OUTPUT.OK,.BUT.
. 0-5.V.OUTPUT.DOESN'T
. WORK
H.. LOOP.AND.0-5V.OUTPUTS.
. OK,.BUT.OPEN.COLLECTOR. .
. PULSE-OUT.OUTPUT.
. DOESN'T.WORK.
10
Response.Time
0.3.second
0.7.second
1.3.second
2.6.second
5.2.second
PROBABLE CAUSE
1.. Loop.not.supplying.power.
. .
2.. Loop.connections.bad.
3.. Transmitter.is.faulty.
1.. 4.mA./.20.mA.setpoints.bad.or.not.set.
2.. No.input.signal.
3.. Input.connections.bad.
4.. Transmitter.is.faulty.
1.. 4.mA./.20.mA.setpoints.bad.or.not.set.
. .
2.. Short-circuit.between.Loop.(–).and.
. LOCAL-COM.circuits
1.. 4.mA./.20.mA.setpoints.bad.or.not.set.
.
. short,.especially.for.slow.input.signal
2.. Input.connections.bad.
. .
long,.especially.for.fast.input.signal
1.. 0-5.V.output.loaded.too.heavily.
1.. No.pull-up.resistor.or.pull-up.power.
.
In.normal.operation,.the.transmitter.always.averages.two.
sequential.input.readings..The.time.delay.from.an.abrupt.
change.in.input.frequency.to.a.final,.stabilized.output.
reading.is.always.twice.that.shown.in.the.above.table.
MAINTENANCE
Check. cable-entry. seals. periodically.. Tighten. and/or.
apply.sealant.if.needed..This.is.especially.important.in.
environments.containing.heavy.concentrations.of.dust,.
oil.mist,.or.other.residue.
Check.all.wiring.connections.occasionally.for.oxidation.
or.corrosion..Clean.and.re-seat.if.such.conditions.are.
noted.
If. necessary,. check. and. re-seat. any. connections. that.
may. have. been. subjected. to. strain. (during. rework. or.
construction,.for.example).
CORRECTIVE ACTION
Be.sure.loop.power.supply.is.present.and.working,.and.has
correct.polarity.
Check.all.loop.connections.for.open-.or.short-circuits.
Replace.transmitter.
Perform.new.setpoint.procedure.for.both.4.mA.and.20.mA.points.
Verify.presence.of.input.signal.at.terminal.block.
Check.all.signal-input.connections.for.open-.or.short-circuits.
Replace.transmitter.
Perform.new.setpoint.procedure.for.both.4.mA.and.20.mA.points.
Check.all.Loop.and.LOCAL-COM.circuitry.for.shorts.
Perform.new.setpoint.procedure.for.both.4.mA.and.20.mA.
Select.a.longer.response-time.setting.
Check.all.signal-input.connections.for.intermittent.open-.or
short-circuits.
Select.a.shorter.response-time.setting.
Be.sure.0-5.V.load.impedance.is.at.least.1000.ohms.(1KΩ).
Be.sure.pull-up.resistor.and.pull-up.power.present,.with.correct
polarity.