User guide

28
IM 12D08N05-01E
5-8. Fail
A fail contact is energized when a fail situation
occurs.Failsituationsareconfiguredinsecton
5-12.ForSOFTFailsthecontactandthedis-
playonLCDarepulsating.ForHARDFailsthe
contactandthedisplayonLCDareenergized
continuously.OnlycontactS4isprogrammed
as a fail-safe contact. This means that contact
S4willbede-energizedwhenafailsituation
occurs.
Hard Fail Only
ThecontactreactstoHardFailsOnly
Hard + Soft fail
ThecontactreactstoHardandSoftFails
5-9. Simulate
The contact can be switched on/off or a
percentageofoutputcanbesimulated.On/Off
enables the user to manually switch a contact
on or off. The percentage is an analogue value
and represents the on time per period. The
Duty Cyde Period time (see figure 5-4) is used
as a period for percentage simulation. Note that
the (simulated) settings of the contacts become
visibleinmeasuringmodeandafterHOLDhas
ended c.q. has been overruled. A warning is
activated in case of a simulated output contact.
5-10. Water for Injection Monitoring
(USP 645 and EU 0169).
Setting up EXA SC450 for WFI monitoring
1. Afunction“USPlimitexceeded”isdefined
as an error code on sec. 5-12, Errors 2/3.
This can be set to off/warn/fail according
to your requirement. This function can
bemodifiedbythefunction“USPsafety
margin”in%.Thisisapercentage
oftheWFIconductivityvalueatthat
temperature that serves as safety margin.
This is independent of what is being
measured. The display shows this error
whenthewaterqualityexceedstheWFI
conductivity limits as set in stage 1.
2. We have introduced uncompensated
conductivityintheDISPLAYmenu.IntheLCD
display the user can read the temperature
and the raw conductivity to compare his water
qualitywiththeWFItable.
3. WehaveaddedaUSPfunctiontothe
contactallocation.ThecontactoutputS1
canbeselectedasUSPalarmifthefunction
“USPlimitexceeded”hasbeenselected.
 ThecontactcloseswhentheUSPlimitis
reached.
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
μS/cm
USP
Safety
Margin
25
50
75
100
˚C
Figure 5-6. USP Safety Margin
Limitofuncompensatedconductivityasfunction
oftemperatureasdefinedforWFI.USPsafety
marginsetas20%willclosethecontactat80%
of the conductivity value at all temperatures.
Forexample,ifthetemperatureis64ºC.and
thesafetymarginisadjustedfor20%,thenthe
contactclosesat0.8x2.2μS/cm.=1.76μS/cm.
(2.2 μS/cmistheWFIlimitat64ºC).Inresistivity
mode the contact will close at an uncompensated
resistivity of 1/1.76 μS/cm.=0.568Mohm.
Recommended Commissioning settings when
monitoringWFIina>80ºCWFIinstallation.
Commissioning
Measurement Set up
Measure Conductivity only
Temp Compensation automatic
Conductivity 1 None
Error Configuration (Errors 2/3)
 USPlimitexceeded Warn
Output Setup
 S1   USP
  USPsafetymargin 10%
 S2   Alarm
Parameter Temperature
  Setpoint  80C
  Direction Low
Delay Time 0.2 s
Expiry Time 0 (disabled)
5-11. Input contacts
TheterminaloftheSC450Gprovidesforanin-
putcontact(seeFigure3-7).Thisinputcontact
can be used to switch the range of the outputs.
The range can be increased by 1 decade.
This is available for only mA1 output.