Seametrics IP80-Series - Manual (Page 9)

Page 9
MaINtENaNcE
Sensor Replacement.­­­­­­­­­­­­It­­­­is­­­­very­­­­unusual­­­­for­­­­a­­­­sensor­­­­to­­­­
require­­­­replacement­­­­in­­­­normal­­­­use.­­­­­­­­The­­­­primary­­­­cause­­­­of­­­­
sensor­­­­failure­­­­is­­­­overvoltage­­­­(inadvertent­­­­connection­­­­of­­­­high­­­­
voltage,­­­­for­­­­example)­­­­or­­­­incorrect­­­­polarity­­­­on­­­­hookup.­­­­­­­­The­­­­
sensor­­­­is­­­­replaced­­­­by­­­­removing­­­­the­­­­strain­­­­relief,­­­­then­­­­thread-
ing­­­­out­­­­the­­­­sensor­­­­retainer­­­­plug.­­­­Remove­­­­the­­­­entire­­­­sensor­­­­
capsule­­­­by­­­­pulling­­­­on­­­­the­­­­cable.­­­­The­­­­new­­­­sensor­­­­capsule­­­­
can­­­­then­­­­be­­­­installed.­­­­Replace­­­­the­­­­retainer­­­­plug,­­­­and­­­­then­­­­
replace­­­­and­­­­tighten­­­­the­­­­strain­­­­relief.­­­­
Rotor Replacement.­­­­­­­­­­­­It­­­­is­­­­unusual­­­­for­­­­a­­­­rotor­­­­to­­­­require­­­­
replacement­­­­due­­­­to­­­­damage­­­­sustained­­­­in­­­­normal­­­­service.­­­­­­­­
More­­­­commonly,­­­­the­­­­meter­­­­is­­­­dropped­­­­while­­­­it­­­­is­­­­out­­­­of­­­­the­­­­
pipe.­­­­­­­­Another­­­­reason­­­­for­­­­rotor­­­­replacement­­­­is­­­­shaft­­­­wear­­­­
after­­­­long­­­­service.­­­­Rotors­­­­are­­­­easily­­­­field-replaced.
To­­­­install­­­­a­­­­rotor,­­­­follow­­­­these­­­­steps:
1.­­­­ Unscrew­­­­the­­­­threaded­­­­bearing­­­­housings­­­­to­­­­expose
­­­­ the­­­­shaft­­­­ends.­­­­­­­­If­­­­bearings­­­­are­­­­being­­­­replaced,
­­­­ back­­­­them­­­­completely­­­­out.
2.­­­­ Remove­­­­the­­­­rotor.­­­­­­­­Put­­­­the­­­­new­­­­rotor­­­­in­­­­its­­­­place.
3.­­­­ Thread­­­­in­­­­one­­­­bearing­­­­housing­­­­part­­­­way,­­­­then­­­­the
­­­­ other.­­­­­­­­Take­­­­care­­­­to­­­­start­­­­the­­­­end­­­­of­­­­the­­­­shaft­­­­into
­­­­ the­­­­bearing­­­­hole­­­­before­­­­tightening­­­­further.­­­­
4.­­­­ Screw­­­­in­­­­bearing­­­­housings­­­­until­­­­they­­­­bottom.
­­­­ Note: Do not use excessive force.
5.­­­­ Check­­­­for­­­­free­­­­spin.­­­­­­­­Blowing­­­­lightly­­­­on­­­­the­­­­rotor
­­­­ should­­­­result­­­­in­­­­it­­­­spinning­­­­rapidly­­­­and­­­­coasting­­­­to­­­­a
­­­­ smooth­­­­stop.
caution:­­­­Never­­­­remove­­­­the­­­­u-clip­­­­retainer­­­­
when­­­­the­­­­pipe­­­­is­­­­under­­­­pressure.­­­­­­­­Always­­­­
remove­­­­pressure­­­­from­­­­the­­­­pipe­­­­before­­­­at-
tempting­­­­to­­­­remove­­­­the­­­­meter.­­­­­­­­Removal­­­­
under­­­­pressure­­­­may­­­­result­­­­in­­­­damage­­­­or­­­­
serious­­­­injury.
Signal troubleshooting.­­­­ ­­­­ The­­­­ flow­­­­ sensor­­­­ has­­­­ only­­­­ one­­­­
moving­­­­part,­­­­the­­­­rotor.­­­­­­­­If­­­­this­­­­is­­­­turning­­­­properly­­­­and­­­­there­­­­
is­­­­no­­­­signal,­­­­the­­­­magnetic­­­­sensor­­­­is­­­­not­­­­operating­­­­properly.­­­­­­­­
To­­­­check­­­­the­­­­signal,­­­­apply­­­­12­­­­Vdc­­­­power­­­­to­­­­the­­­­red­­­­(+)­­­­and­­­­
black­­­­(-)­­­­leads.­­­­­­­­Set­­­­a­­­­multimeter­­­­to­­­­voltage­­­­reading.­­­­­­­­Put­­­­
the­­­­positive­­­­multimeter­­­­lead­­­­on­­­­the­­­­red­­­­wire­­­­and­­­­the­­­­nega-
tive­­­­lead­­­­on­­­­the­­­­white­­­­wire.­­­­Slowly­­­­turn­­­­the­­­­rotor.­­­­­­­­Voltage­­­­
reading­­­­should­­­­swing­­­­between­­­­-12­­­­Volts­­­­and­­­­0­­­­Volts­­­­as­­­­the­­­­
rotor­­­­turns.­­­­­­­­If­­­­it­­­­does­­­­not,­­­­the­­­­solid-state­­­­magnetic­­­­sensor­­­­
is­­­­not­­­­working­­­­properly.­­­­­­­­Checking­­­­for­­­­continuity­­­­is­­­­not­­­­a­­­­
useful­­­­test­­­­of­­­­these­­­­sensors.
Sensor Replacement
1)­­­­ Loosen­­­­and­­­­unthread
­­­­­­­­­­­­­­­­­­­­Strain­­­­Relief
2)­­­­ Remove­­­­Sensor­­­­Retainer
­­­­
Plug­­­­by­­­­inserting­­­­a
­­­­ screwdriver­­­­blade­­­­into
­­­­ one­­­­side­­­­of­­­­the­­­­slot­­­­and
­­­­ turning
3)­­­­ Remove­­­­the­­­­Sensor
­­­­
Capsule­­­­by­­­­pulling­­­­on
­­­­ the­­­­cable
4)­­­­ Reverse­­­­the­­­­process
­­­­
to­­­­replace
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(Includes Dates Before 1/1/201
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