Troubleshooting Series 776 Low-Pressure Actuator; Troubleshooting Series 746 Dry Accelerator; Troubleshooting System - Victaulic FireLock 758-LPA Series Installation, Maintenance, & Testing Manual

TROUBLESHOOTING SERIES 776 LOW-PRESSURE ACTUATOR

Problem
When you pull up on the auto vent knob, the
knob does not stay 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 SERIES 746 DRY ACCELERATOR

Problem
The system valve operates
without sprinkler activation.
Dry accelerator does not
operate within a 5-psi (34 kPa)
pressure drop in system air
pressure.
Dry accelerator does not set up
properly (cannot get pressure on
upper gauge, and button pops
up immediately when pressure is
introduced).

TROUBLESHOOTING SYSTEM

Problem
Valve operates without sprinkler activation.
Water leaking from drip check valve.
Air leaking from drip check valve.
Clapper will not latch closed.
Water leaking from piston assembly.
Air leaking from piston assembly.
Possible Cause
Not enough air is getting to the Series 776.
There is a broken seal in the Series 776.
The air chamber is not set.
The strainer on the Series 776 is clogged.
There is a ripped diaphragm in the Series 776.
The solenoid is not open.
The strainer on the piston charge line is clogged.
The solenoid is not energized.
Possible Cause
Loss of air pressure in the lower
inlet chamber.
Loss of air pressure in upper air
chamber of dry accelerator.
Air decay rate of system is too slow.
Dry accelerator is installed upside
down.
Possible Cause
Loss of air pressure in system or trim.
Pressure switch on air compressor is set low, or
compressor is not operating.
Water is getting past clapper seal and into
intermediate chamber.
Water is under clapper seal.
Air is getting past clapper seal and into
intermediate chamber.
Water is under clapper seal.
No water pressure on piston.
Auto drain is not set.
Diaphragm is damaged.
Piston rod seal is damaged.
Increase the air pressure going into the Series
776.
If the above procedure does not work, contact
Victaulic.
Make sure the air chamber of the Series 776 is
set.
Replace the strainer on the Series 776, per the
instructions on page 33.
If water still leaks through the Series 776, contact
Victaulic.
Make sure the solenoid is energized OPEN.
Disassemble and clean the piston charge line
strainer.
Activate the electrical portion of the system to
energize the solenoid.
Check for air loss at lower chamber seal. If a leak is present, turn adjustment
nut counterclockwise to seal.
Check for any leaks in system and trim. Confirm proper operation of air
maintenance device.
Apply soapy water to all dry accelerator joints, and check for leaks. Repair any
leaks and re-test.
Make sure there are no restrictions in the inspector's test connection.
If the above procedures do not work, contact Victaulic.
Remove dry accelerator from trim, and turn unit around so that the button is
facing down (toward Series 776).
Check for system leaks. Confirm proper
operation of air maintenance device. Consider
installing a low-air supervisory switch.
Increase "ON" setting on pressure switch, and
check compressor for proper operation.
Check clapper seal and valve body seat ring for
physical damage or foreign material.
Inspect clapper seal to make sure no water is
under seal. If water is present, remove and
replace seal, per instructions on page 28.
Check clapper seal and valve body seat ring for
physical damage or foreign material.
Inspect clapper seal to make sure no water is
under seal. If water is present, remove and
replace seal, per instructions on page 28.
Check water pressure in piston charge line.
Set auto drain.
Contact Victaulic.
Contact Victaulic.
34
Solution
Solution
Solution