TSI Instruments PRESSURA 8630-PM, Operation And Service Manual

Page: 42 / 49

Part Two
36
Symptom Possible Cause Corrective Action
Alarm relays
don't work. Alarms are turned
off.
Incorrect wiring.
Alarm is from
second sensor.
Alarm is from flow
station.
Relay may be
defective. Press TEST key. The individual alarm set points will
display. If all alarm set points are zero, alarm relay is not
active, so relay will not be required to change state.
Check the wiring from PresSura controller relay's output
to the device that is connected to the relays.
The relay contacts only work for primary pressure
alarms. The relays do not activate when a second
sensor or flow alarm condition occurs (DIM light and
audible do activate). This is because the primary
pressure alarms are the most important or have the
highest priority.
Disconnect the wiring from relay contact pins 13 and 14
for low alarm relay and pins 25 and 26 for high alarm
relay. Go into DIAGNOSTICS menu, LOW ALM REL or
HIGH ALM REL. Connect an ohmmeter to relay
terminals to verify contact open and closes. Press
the

/

key to manually trip the relay. If relay responds
(contact opens and closes), the device connected is
incompatible or defective.
If relay doesn’t respond, relay
is defective (may be caused by incompatible device).
Replace DIM.
"DATA ERROR"
flashing on
display. DIM was hit by
electrical
disturbance.
All data may be lost or changed. Review all configuration
parameters. DATA ERROR
is removed by pressing the
RESET key.
Displayed
pressure wildly
fluctuating. Exhaust or supply
system is
unstable.
Supply or exhaust
air is affecting the
sensor. Check supply and exhaust flow for stability. Verify
reference pressure is not fluctuating.
Check location of supply air diffusers and exhaust
grilles. They should be as far from pressure sensor as is
realistic, 6 feet preferred, 2½ feet minimum. Supply
diffuser terminal throw velocity must be less than 10
ft/min at the sensor. Relocate supply or exhaust as
needed.
Electric actuator
“chatters” or
excessively hunts
at set point.
Ground loop
present. This symptom occurs when multiple devices are being
ran off one transformer. Each system must be powered
by its own transformer or have an isolation transformer
installed.
NOTE: Unit may hunt due to speed of system and may
not be tied to ground loop problem.