WÄRTSILÄ PAAE051728, Instruction Manual

Page: 370 / 394

23.5.5 Solenoid valves
The solenoid valves used on the engines are 3-way type valves of
make E. Seitz. They can, depending on the application, either be
normally open or normally closed. The nominal operation voltage
is 24 V DC, and the solenoids have a voltage tolerance of -15 % to
+10 %. The coil has a power rating of 11 W and it has built-in
voltage suppression and reverse polarity protection diodes.
23.5.6 Relay Module
The Relay Module is a device that executes orders from the MCU
by means of activating solenoids etc. It also serves as a safety
backup system when the main safety system doesn’t work prop-
erly or if the rest of the system is out of operation. Most of the
hardwired signals as the emergency switch etc. are connected to
the Relay Module. Also power supply for the whole system is
provided by the Relay Module.
Layout of the Relay Module
Unlike the other units of the WECS the Relay Module has no
processor or software. Consequently the Relay Module is a totally
hardware driven unit.
The Relay Module consists of the following functional blocks:
·
speed measuring block (backup),
·
lube oil shutdown block (backup),
·
optional shutdown block (backup),
·
MCU stop/shutdown block,
RELAY
MODULE
RM-11
BACKUP U1 U2 U3 U4 U5
+ 12 VDC
OVERSPEED
BY-PASS
LUBE OIL SHUTDOWN
LUBE OIL SHUTDOWN
BLOCKING
OPTIONAL SHUTDOWN
MCU STOP/SHUTDOWN
LOCAL STOP
OVERSPEED SHUTDOWN
EMERGENCY STOP
WECS WATCHDOG
STOP/SHUTDOWN OVERRIDE
SHUTDOWN RESET
STOP RELAY
LOCAL START BLOCKING
LOCAL START
WECS START
FUEL LIMITER
SLOW TURNING
FAILURE ALARM
SPEED SWITCH 1
SPEED SWITCH 2
SPEED PULSE
LUBE OIL SHUTDOWN SWITCH FAILURE
OPTIONAL SHUTDOWN SWITCH FAILURE
ENERGIZED STOP SOLENOID FAILURE
EMERGENCY STOP FAILURE
SHORT CIRCUIT
Fig 23-29
402313200113
23 Instrumentation and Automation 32-200115/II
23-36 WÄRTSILÄ 32