Troubleshooting - Series 776 Low-Pressure Actuator; Troubleshooting - Series 746-Lpa Dry Accelerator; Troubleshooting - System - Victaulic FireLock NXT 768 Series Installation, Maintenance, And Testing Manual

INSTALLATION,MAINTENANCE,ANDTESTINGMANUAL
FireLockNXT™DryValve
SERIES768
TROUBLESHOOTING–SERIES776LOW-PRESSUREACTUATOR
Problem
When the Auto Vent Sleeve of the Series 776 Low-Pressure Actua-
tor is pulled up, the screw does not stay set in the "UP" position.
Water is leaking through the Series 776 Low-Pressure Actuator.
No water is passing through the Series 776 Low-Pressure Actuator.
TROUBLESHOOTING–SERIES746-LPADRYACCELERATOR
Problem
The valve operates without sprinkler activation.
The Series 746-LPA Dry Accelerator does not operate within a
5-psi/34-kPa/0.3-Bar pressure drop in system air pressure.
The Series 746-LPA Dry Accelerator does not set up properly
(cannot get pressure on the upper gauge, and the button pops up
immediately when pressure is introduced).
TROUBLESHOOTING–SYSTEM
Problem
The valve operates without sprinkler activation.
Water is leaking from the drip check located in the alarm line.
Air is leaking from the drip check located in the alarm line.
The clapper will not latch closed.
Water is leaking from the diaphragm assembly.
Air is leaking from the diaphragm assembly.
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PossibleCause
The Series 776 Low-Pressure Actuator is not receiving enough air.
The Series 776 Low-Pressure Actuator has a broken seal.
The air chamber of the Series 776 Low-Pressure Actuator is not set.
The strainer on the Series 776 Low-Pressure Actuator is clogged.
The Series 776 Low-Pressure Actuator has a ripped diaphragm.
The strainer on the diaphragm charge line is clogged.
PossibleCause
There is a loss of air pressure in the lower inlet chamber of the Series
746-LPA Dry Accelerator.
There is a loss of air pressure in the upper air chamber of the Series 746-
LPA Dry Accelerator.
The air decay rate of the system is too slow.
The Series 746-LPA Dry Accelerator is installed upside-down.
PossibleCause
There is a loss of air pressure in the system or trim.
The pressure switch on the air compressor is set too low, or the compressor
is not operating properly.
Water is getting past the clapper seal and into the intermediate chamber
of the valve.
Water is under the clapper seal.
Air is getting past the clapper seal and into the intermediate chamber of
the valve.
Water is under the clapper seal.
There is no water pressure on the diaphragm.
The Auto Drain is not set.
The diaphragm is damaged.
The diaphragm is damaged.
Solution
Increase the air pressure going into the Series 776 Low-Pressure Actuator.
If the above procedure does not work, contact Victaulic.
Make sure the vent seal of the Series 776 Low-Pressure Actuator is in the set
position and the air chamber is pressurized.
Replace the strainer screen of the Series 776 Low-Pressure Actuator. Refer
to the "Replacing the Strainer Screen for Series 776 Low-Pressure Actuators"
section.
If water still leaks through the Series 776 after performing the above
procedures, contact Victaulic.
Disassemble and clean the diaphragm charge line strainer. Refer to the
applicable trim drawing for details.
Solution
Check for air loss at the lower chamber seal. If a leak is present, turn the
adjustment nut counterclockwise to seal.
Check for any leaks in the system and trim. Confirm that the AMTA is
operating properly.
Apply soapy water to all joints around the Series 746-LPA Dry Accelerator to
check for leaks. Repair any leaks and re-test.
Make sure there are no restrictions in the remote system test valve
(inspector's test connection).
If the above procedures do not work, contact Victaulic.
Remove the Series 746-LPA Dry Accelerator from the trim, and turn the unit
around so that the vent seal "button" is facing down (toward the Series 776
Low-Pressure Actuator).
Solution
Check for any leaks in the system and trim. Confirm that the AMTA is operat-
ing properly. Consider installing a low-air supervisory switch.
Increase the "ON" setting of the air compressor's pressure switch, and check
the air compressor for proper operation.
Check the clapper seal and valve body seat ring for physical damage and
foreign material.
Inspect the clapper seal to make sure no water is under the seal. If water is
present, remove and replace the seal. Refer to the "Removing and Replacing
the Clapper Seal" section.
Check the clapper seal and valve body seat ring for physical damage and
foreign material.
Inspect the clapper seal to make sure no water is under the seal. If water is
present, remove and replace the seal. Refer to the "Removing and Replacing
the Clapper Seal" section.
Check the water pressure in the diaphragm charge line. Make sure the
restrictor in the diaphragm charge line is clean.
Set the Auto Drain by pulling up on the Auto Drain Sleeve.
Contact Victaulic.
Contact Victaulic.
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