Bell & Gossett S14334B Technologic 5500 Series Variable Primary Pump and Valve Controller - Manual (Page 6)

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NOTE: The information contained in this manual is intended to assist operating personnel by providing information on the char -
acteristics of the purchased equipment.
It does not relieve the user of the responsibility to adhere to local codes and ordinances and the use of accepted practices in
the installation, operation and maintenance of this equipment.
Further information pertaining to the installation, operation, and maintenance of your Technologic 5500 series pump controller
can be found in the I.O.M.s for the associated equipment provided see Section 5, Maintenance, for a list of relevant manuals.
Glossary of Terms
AFD
Adjustable Frequency Drive; converts a constant power input
into a variable power output for the motor; a device for con-
trolling motor speed
Alternation
Process of determining which pump will serve as lead pump
and which pump will serve as lag pump
Bypass
Controller bypasses the AFD, pumps stop running in variable
speed mode and run at constant speed (50 Hz / 60 Hz)
Bypass Valve
Modulating valve that controls the minimum flow required by
chillers
Destage
To turn off a lag pump
EOC
End of Curve; point at which a pump is staged or destaged
I.O.M.
Installation Operation Manual
Isolation Valve
Two way control valve that isolates flow from standby chillers
Lag pump
Standby pump that activates only when lead pump alone
cannot efficiently provide sufficient pressure or flow rate
Lead pump
Duty pump which runs continuously until a standby pump is
required
LED
Light emitting diode, located on OIP and controller
OIP
Operator Interface Panel
O.L.
Overload: device to protect a motor from overheating
PID
Proportional Integral Derivative; 3 variables required for error
control
Process Variable
Signal generated by a sensor that is set up to control the
system
Proof timer
Minimum time period before controller acknowledges an
input; time period for which a signal must be stable before it
is accepted by the controller as a sustained and valid signal
RTC
Real time clock
RTD
Resistive temperature device used to supply temperature
signals to the PLC
Stage
To start a lag pump