Koso REXA Electraulic Xpac, Installation And Operation Manual

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Xpac
Installation Manual -- Version 5.1 (5/08)
G-4
REXA
Electraulic Actuators & Drives
G.1.2 ADDED FUNCTIONALITY TO THE ELECTRONICS
Four new parameters have been added to the PCP to accommodate
accumulator functions. These may be found under the
Obd
branch:
1&2. Parameters rH & rl . These are the reference pressure settings
that the PCP compares to the output of the pressure transducer.
rH is the high or limit pressure of the recharge cycle. rl is the
minimum pressure allowed before a recharge cycle is performed.
These parameters can be set in 100 psi increments.
3.
Parameter,
Rt
, recharge time, allows the setting of the maximum
time allowed for a recharge cycle. Rt is displayed as an integer
with a settable range of 10 to 1000, in ten second steps, and
represents the number of seconds allowed for a recharge cycle.
A recharge cycle ends when either the pressure transducer out-
put equals
rH or the recharge time expires. In either case, the
actuator resumes tracking the control signal.
4. Parameter Fd defines Fail direction. Fail direction is the direction
the Accumulator will drive the actuator on an Accumulator trip
condition.
Fd has two settings, Pl or PH . If the accumulator is
configured to drive the unit toward
Pl
on a trip condition, the
Fd
should be set to Pl . Likewise, if the accumulator is configured
to drive the unit toward
PH
on a trip condition, then
Fd
should
be set to PH . This parameter is typically factory set.
The contact input (P1&P3) provides a trip signal input. When the trip
signal is active, the PCP will de-energize the solenoids connected to
the surge board, allowing the accumulator to drive the actuator to its
fail position. The “trip” function operates without the aid of the motor.
Loss of electrical power will also initiate a failure.
A second input to the PCP is provided by the 4-20 mA output of the
pressure transducer on the accumulator. When the accumulator is fully
charged, accumulator pressure will be equal to the
rH set point. After
a trip (or multiple partial trips) , accumulator pressure will fall below the
rl parameter set point , indicating to the PCP the need to recharge the
accumulator.
If accumulator pressure should fall below rl during normal operation,
relay K3 (alarm) will be de-energized. In this condition, the rated output
of the actuator may not be available upon a failure.
These four parameters are fac-
tory set. Do not change without
consulting REXA.
Changing this parameter does
not change the actual fail direc-
tion of the actuator. As with a
spring fail unit, failure direction
(extend, retract, CW, CCW) is a
mechanical configuration. The
correct failure direction must
be specified when the unit is
ordered.
The trip signal may be a 24 –
120 volts AC or DC input
Relay K3 on the limit switch board
will only indicate low accumulator
pressure. All other alarm functions
are available at the alarm relay on
the position transmitter board.