Manitowoc 999, Service And Maintenance Manual

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Reference
Only
Manitowoc
Published 05-16-17, Control # 233-03
1-9
999 SERVICE/MAINTENANCE MANUAL INTRODUCTION
1
EPIC

PROGRAMMABLE CONTROLLER
See Figure 1-4
The 999 crane’s pumps, motors, control handles, sensors,
limit switches, selectors, solenoid valves, brakes, pawls,
clutches and alarms are controlled with the EPIC (Electrical
Processed Independent Control) system. This simplifies the
crane’s electrical control system by avoiding mechanical
c o n t r o l s w i t c h e s a n d r e l a y s . Sta n d a r d o r c u s t o m
programming allows the PC (Programmable Controller) to
adjust to each operational mode’s acceleration rate and
speed, apply brakes, retract pawls, and engage clutches-if
equipped.
The PC receives and sends both analog and digital input/
output signals that are AC or DC voltages or currents in a
pulse train. Digital input/output signals are 12-volt nominal
voltages that are either off 0 or on 1.
The PC uses the binary system. The binary system is based
on binary multiples of 2, and only recognizes 0 for off or 1 for
on voltages. Basic counts of this system are exponents of the
number 2. These exponents are formed in words, called
bytes, of eight numbers each. The eight numbers are 1, 2, 4,
8, 16, 32, 64, and 128 for an 8-bit controller or a combination
of up to 255 bytes. These bytes represent electrical inputs to
the controller. The controller processes this information by
comparing it to programming requirements and data
information. The PC then provides appropriate output
commands to crane control devices.
Digital display screen shows operating conditions, operating
limits, and system faults monitored by the PC. Access
information by scrolling to the desired display screen with
scroll switch. System messages are shown in Tables 1, 2,
and 3 of the Digital Display Readings in Operator Manual.
Switches, limits, selectors or control handles send input
voltage command signals to the PC. The PC compares these
input voltages with feedback voltages received from system
monitoring sensors, memory information, and directives
entered into programming. Monitoring sensors includes; limit
switches, pressure senders, speed encoders, engine RPM
indicator, hydraulic fluid and temperature probes, and boom/
mast/jib angle sensors. The PC then sends an output signal
to pump EDC (Electrical Displacement Control) and digital
outputs to solenoid valves to control system operation rates
and direction. Digital outputs to solenoid valves operate
brakes, pawls, and clutches that correspond with controls or
control handle commands.
Pressure senders measure system pressures and supply the
PC with input voltages that are stored in pressure memory.
Pressure senders provide information on the required
pressure to hold the load drum or boom hoist and prevent
them from lowering after releasing drum brake. Pressure
senders include: front drum, rear drum, auxiliary drum, boom
hoist, right travel, left travel, swing right, swing left, and
accessory system (low-pressure side of rear drum).
Drum speed encoders detect speed and direction of drum
movement. The PC receives this information as two out-of-
phase square wave voltages that are converted to "counts".
The PC compares control handle voltage with pump output
to determine when to vary pump stroke. Speed encoders
include front drum shaft, rear drum shaft, boom hoist drum
shaft, and auxiliary drum flange.
Universal boom top junction box monitors boom, luffing jib, or
fixed jib components and transmits information to the PC.
See RIN (Remote Input Node) Display Readings in 999
Operator Manual.
FIGURE 1-4
Monitoring
Voltages Out
Command Voltages In
Programmable
Controller
Processing
Memory
Switches
Brake
Valve
Drum
Speed
Drum
Pressure
Sender
Motor
Pump
Selectors
Limit
Switches
Control
Handles
Voltages to
Counts to
Voltages
Limit Switches
Digital Display
Brake Gear
Reducer
999CSM1-103
PCP EDC