Specifications
Governor's
Park
Condominium 777 Washington Street
Denver,
CO
2.02 CONTROL
SYSTEM
VWF
DRIVE
A. The existing
US
Elevator control system shall be removed and a new microprocessor control
with 2-car group shall be furnished and installed. Remove the Motor Generator Sets and install
new Variable Voltage Variable Frequency Drives. (VVVF Drives)
B.
A position selector shall provide positive means
of
determining the position
of
the elevator in
the hoistway at all times. A digital encoders shall be provided on the elevator or in the ma-
chine room. Analog systems utilizing perforated steel tapes are not pennitted. The encoder
unit mounted on the top
of
the car or on the governor shall be capable
of
providing a signal
as
to the position
of
the car in the hoistway.. Floor location for leveling shall be determined via
magnetic strips affixed
to
the brackets or tapes to define the floor-leveling zone. The position
selector shall provide 1/8" resolution accuracy for the entire length
of
the hoistway.
C.
A digital velocity transducer shall be mounted on the machine
to
communicate the machine
speed to the individual car computer. Analog systems utilizing Tachometers are not permitted.
The car computer shall continuously compare the machine speed to the optimum velocity pro-
file and point
of
slowdown for the target floor and control the acceleration and retardation
to
final stop
regardl~ss
of
travel or load in the
car.
Adjustments
to
the pattern shall be performed
to the elevator prior
to
committing the selected ride pattern
to
the car computer's memory.
Data shall be stored in a non-volatile memory in the system to prevent malevolent use and be
accessible only
to
authorized technicians. The hoistway position selector device shall provide
a visual display
of
the current shaft count or synchronous position plus a bar graph indication
of
the pattern profile/elevator speed. Means for adjusting the test speed, pattern precondition,
soft start acceleration and deceleration shall be included in the car controller. Battery backup
memory shall be provided
to
retain the current floor count in the event
of
a power shutdown.
Nominal shaft counting errors shall be corrected each time the elevator stops at a floor or ter-
minallanding
to
reset shaft counts.
D.
The control system shall be designed to automatically bring the car to a floor landing. The
stop shall be smooth without any sudden brake application. The floor approach shall be with-
out any hesitation or delay in time. Floor sensing devices shall correct for overtravel and un-
dertravel and shall maintain the car within a maximum
of
1/8"
of
the floor line, regardless
of
rated capacity, load or direction
of
travel.
E.
The controllers shall be enclosed in properly ventilated metal cabinets with sides and top, and
with hinged access doors on the front and the back. Rubber mats shall be installed on the floor
in front and behind each controller, starting panel and selector,
as
required, for electrical
grounding protection
of
the equipment.
F.
All controller printed circuit boards, discrete components, switches, and other items
of
control
equipment shall be mounted on a common panel or individual panels which shall be made
of
an approved, moisture-resisting, noncombustible material which shall be securely mounted in a
substantial, self-supporting steel frame with fastenings suitable for panel demounting. A vibra-
tion absorbing mounting shall be provided for the steel frame,
if
necessary, to eliminate per-
ceptible vibration.
G.
Electro-mechanical switches and relays shall be used where heavy current is supplied and/or
on safety circuits required by the governing Elevator Codes.
Elevator Consulting and Design, Inc.
13