tor. Failure to perform Step ‘e’ of the Setting Procedure
can permit a small amount of water to enter the Pilot
Chamber of the Accelerator.
Slow Fill of Differential Chamber
Use the following instructions if the time to fill the Differen-
tial Chamber is longer than the maximum value indicated
in Step ‘k’of the Setting Procedure Section.
1. Check to see that the Accelerator was reset per Step ‘h’
of the Setting Procedure Section.
2. Close the system’s main control valve and open the
main drain valve.
3. Check for any sign of external leakage past the Accel-
erator Pressure Gauge, Vent, and Restriction Access
Plug connections.
4. Check for any sign of external leakage past the Reset
Knob and Cover Gasket.
5. Close the Accelerator Control Valve.
6. Gently insert a 3/32 inch or smaller diameter probe into
the Relief Port. If the probe can be inserted more than
1/4 inch then the Lever has not reset and the Accelera-
tor must be disassembled for internal inspection. See
the instructions for Accelerator Disassembly and Reas-
sembly.
7. Slowly remove the Accelerator Vent Plug to bleed all
pressure from the Differential Chamber and then slowly
remove the Restriction Access Plug to bleed all pres-
sure from the Pilot Chamber.
8. Replace the Restriction and then the Restriction Access
Plug.
9. Place the fire protection system back in service in ac-
cordance with Steps ‘i’ through ‘n’ of the Setting Proce-
dure Section.
Unexplained Accelerator Trip
Use the following instructions if there is an unexplained
accidental trip of the Accelerator.
1. Verify that the connection from the Accelerator to the
system piping is installed in accordance with Instruction
No. 4 of the Installation Section. Correct if necessary.
2. Verify the time to fill the Differential Chamber as de-
scribed in Step ‘k’ of the Setting Procedure Section. If
the time to fill the Differential Chamber to 10 psi is
longer than the maximum indicated value, then follow
the instructions given under “Slow Fill of Differential
Chamber”.
3. If the time to fill the Differential Chamber is within the in-
dicated range of values, then investigate for and correct
any condition which could result in excessive leakage of
system air pressure.
Fast Fill of Differential Chamber or Long Time to Ac-
celerator Trip
Use the following instructions if the time to fill the Differen-
tial Chamber is shorter than the minimum value indicated
in Step ‘k’of the Setting Procedure Section.This proce-
dure should also be followed if the time to Accelerator trip
(following opening of the Inspector’s Test Connection) is
significantly longer than expected.
1. Close the system’s main control valve and open the
main drain valve.
2. Close the Accelerator Control Valve.
3. Slowly remove the Accelerator Vent Plug to bleed all
pressure from the Differential Chamber and then slowly
remove the Restriction Access Plug to bleed all pres-
sure from the Pilot Chamber.
4. Using a slotted screwdriver, check the tightness of the
Restriction.
5. Inspect the Restriction’s O-ring seal. The O-ring must be
replaced if there are any signs of nicks, cuts, or deterio-
ration due to age. Replace the Restriction after cleaning
and lubricating its O-ring with a non-petroleum based
grease (such as Dow Corning FS3452). Replace the
Vent Plug and Restriction Access Plug.
6. If the Restriction and its O-ring are found to be in good
condition, then it is likely that there is leakage past the
Plunger. Remove the Cover from the Base. Check that
the six screws securing the Upper Diaphragm Plate to
the Cover are tight.
Inspect the Upper Diaphragm for any sign of cracks, pin
holes or deterioration due to age. Replace the Plunger if
there is any possibility of leakage past the Upper Dia-
phragm.
7. Reassemble the Accelerator and place the fire protec-
tion system back in service in accordance with Steps ‘j’
through ‘n’ of the Setting Procedure Section.
Air Leakage Out Automatic Drain
If there is leakage of air out the Automatic Drain of the
dry pipe valve, after the Accelerator and dry pipe valve
have been placed in service, then it will be necessary to
first determine whether the leakage is past the Accelera-
tor or the dry pipe valve.
Close the Accelerator Control Valve.Slowly remove the
Accelerator Vent Plug to bleed all pressure from the Differ-
ential Chamber and then slowly remove the Restriction
Access Plug to bleed all pressure from the Pilot Chamber.
If leakage out the Automatic Drain persists then refer to
the dry pipe valve Technical Data Sheet for maintenance
instructions.If leakage out of the Automatic Drain stops,
then the Accelerator will have to be taken out of service
and the Accelerator Plug Seat removed for cleaning of
the seat and the lower O-ring area on the Exhaust Valve.
Accelerator Disassembly and Reassembly
(For Internal Inspection As Necessary)
1. Close the system’s main control valve and open the
main drain valve.
2. Close the Accelerator Control Valve.
3. Slowly remove the Accelerator Vent Plug to bleed all
pressure from the Differential Chamber and then slowly
remove the Restriction Access Plug to bleed all pres-
sure from the Pilot Chamber.
4. Break the union connections at the Inlet and Outlet of
the Accelerator and remove it from the line. Plug the
connection to the intermediate chamber of the dry pipe
valve and place the fire protection system in service
while the Accelerator is out for maintenance.
STAR SPRINKLER INC.
2-5.4.10 Page 7
