WinGD X72 - Page 121

Operation
0520−1/A1
Winterthur Gas & Diesel Ltd.
1/ 4
Operation with Exhaust Valve Control Unit Cut Out
1. General 1..........................................................
2. Emergency Operation with Exhaust Valve Closed 1...................
2.1 Cut Out the VCU 1............................................
2.2 Operation with the VCU Cut Out 1..............................
2.3 Replace the Defective VCU or Hydraulic Pipe 1..................
3. Emergency Operation with Exhaust Valve Open 3.....................
3.1 Exhaust Valve − Stop Operation 3..............................
3.2 Cut In the VCU 3..............................................
1. General
If there is a defect in an exhaust valve control unit (VCU), on the hydraulic pipes or on
an exhaust valve, you must repair the defective item immediately.
If this is not possible because the engine must continue to operate, do the procedures
that follow for the related cylinder.
2. Emergency Operation with Exhaust Valve Closed
2.1 Cut Out the VCU
If the exhaust valve is defective or there is a large difference between the closing or
opening time, cut out the VCU.
The exhaust valve stays closed in the emergency operation that follows:
1) Cut out the injection (see 0510−1 paragraph 1).
2) In the LDU−20 get the EXHAUST VALVES page (see 4002−2, paragraph 3.8
Exhaust valve).
3) In the column Exh. Valve pos., select 0 to set the related cylinder to automatic.
4) Disconnect the electrical connection (7, Fig. 1) from the 4/2-way valve (8) of the
related cylinder.
2.2 Operation with the VCU Cut Out
After the procedure in paragraph 2.1 above is completed, the engine can operate
again.
Note: With one or more VCUs cut out, you can operate the engine only at
decreased load. Read and obey the data in 0500−1. Also, the exhaust gas
temperature on the cylinders must not be more than the maximum limit of
515_C.
Replace the defective VCU or hydraulic pipe as soon as possible (see the
Maintenance Manual 5612−1 Servo Oil Rail and 8460−1 Hydraulic Pipe for Exhaust
Valve Drive).
2.3 Replace the Defective VCU or Hydraulic Pipe
1) Stop the engine.
2) Make sure that the servo oil service pump is set to off.
3) Set to off the main bearing oil supply.
4) Carefully open the screw plug (3) to release the pressure in the servo oil rail (2)
(see Fig. 1).
5) Close the screw plug (3).
6) Loosen the screws (6) on the flange (5) to drain the hydraulic pipe (4) through the
check bore (9) in the housing of the VCU (1).
7) Set to on the main bearing oil supply.
8) Replace the defective VCU or the hydraulic pipe (see the Maintenance Manual
5612−1 and 8460−1).
2014
Operation during Unusual Conditions