Parr Instrument Company 6300, Руководство по эксплуатации

Страница: 49 / 130

M
AINTENANCE
& T
ROUBLESHOOTING
6300
9
w w w . p a r r i n s t . c o m
49
WARNING:
This screen allows unconditional and arbi-
trary output control for testing purposes. Be
aware that all user and instrument protec-
tion is disconnected while on this screen.
This is very important and you should take
proper pre-caution.
Make sure the 668DD check valve is installed at the 1.
bottom of the cylinder.
Lock the head into the cylinder and close the calo-
2.
rimeter lid.
Confirm the Exhaust is off.
3.
Turn Bomb Seal on then off to retract the 966DD2 4.
piston.
Turn on O2 Fill to begin filling the bomb. The
5.
bomb will be completely filled in one minute, at
which time O2 Fill should be turned off. This seats
the check valve in the head which in turn seals the
contents of the bomb.
The calorimeter lid can be unlocked at this time.
6.
Activating the Exhaust should initiate a bomb 7.
exhaust within two seconds. If it takes much longer
than two seconds before the bomb begins to vent,
then at least one of the two following conditions
outlined below exist.
If the bomb exhaust is initiated in a timely manner
8.
but fails to complete in 10 seconds, a blockage or
restriction in the bomb exhaust circuit is indicated.
This must be investigated and corrected.
If the bomb fails to exhaust, the 899DD Head Handle
and SN1632HX 8/32 Hex Nut can slowly be removed
to release the pressure in the bomb. See Figure 13-1.
If the piston moves properly with no applied bomb pres-
sure, but still fails to initiate an exhaust of a pressurized
bomb in a timely fashion, at least one of the following
conditions exist:
The 527VB restrictor is partially blocked. 1.
The exhaust line is blocked. 2.
There is a gas leak between the outlet of the sole- 3.
noid and the 1140DD cylinder. This also includes
the 357HCJB O-ring seal on the piston inside of the
cylinder.
The first condition can be eliminated by cleaning or
replacing the 527VB restrictor.
The second condition can be eliminated by replacing
the tubing and clearing all connections.
The third condition can be eliminated by following the
procedure outlined in the section servicing the O-rings
on the 966DD2 piston and carefully inspecting the 1/8
nylon pressure hose and associated compression fittings
for leaks while this circuit is maintained at operating
pressure, using the calorimeter I/O diagnostics. A min-
ute leak will result in a significant reduction in upward
thrust.
Confirm Correct Operation of the A1251DD Solenoid Valve
If the piston does not move, it is worthwhile at this
point to confirm that both sections of the A1251DD are
working properly (Figure F-7). For the location of the
A1251DD assembly (Figure F-4).
Disconnect the 1/8 nylon pressure hose at the elbow
connection nearest the back panel by using a 7/16
wrench. Apply power to the unit and re-enter the I/O
diagnostics. Turn the exhaust output on. The solenoid
should click and oxygen should flow from the elbow
connection on the A1251DD. Turn the exhaust output
off and re-connect the nylon pressure hose. Disconnect
the 1/8 nylon pressure hose at the middle connection.
Activating the bomb seal output should produce a click
from the solenoid and a flow of oxygen at the elbow.
Turn off the bomb seal output and reconnect the nylon
pressure hose. If neither solenoid produces a flow
of gas when activated and the O2 FILL key does not
produce a flow of gas, then, in all likelihood, the 527VB
flow restrictor is plugged and should be replaced. If
only one of the solenoids sources gas when activated,
then the problem must be further diagnosed as either
being electrical (I/O board, solenoid coil or external
wiring) vs. mechanical (in the valve) and dealt with in
an appropriate manner.
If either solenoid sources gas when it is off (i.e. leaks)
then replacement of the entire A1251DD solenoid as-
sembly is indicated. For reference purposes, the normal
upward thrust generated by the 966DD2 piston is 50
pounds. The downward thrust is 20 pounds. Far less
than 20 pounds are required to move the piston in either
direction when the bomb is not pressurized.