GE PQMII, Инструкция по эксплуатации

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CHAPTER 2: INSTALLATION
PQMII POWER QUALITY METER – INSTRUCTION MANUAL 2–15
Each switch input can be programmed with a 20-character user defined name and can be
selected to accept a normally open or normally closed switch. A list of various functions
assignable to switches is shown below, followed by a description of each function.
•
Alarm Relay : When a switch input is assigned to the alarm relay, a change in the
switch status produces an alarm condition and the alarm relay activates.
• Pulse Input 1/2/3/4 : When a switch input is assigned as a pulse input counter, the
PQMII counts the number of transitions from open to closed when the input is
configured as normally open and closed to open when the input is configured as
normally closed. The minimum pulse width required for the PQMII to read the switch is
150 ms. Therefore, for the PQMII to read one pulse, the switch input must be in its
inactive state (closed/open) for a minimum of 150 ms then in its active state (open/
closed) for another 150 ms. See
1.6: Specifications for more details.
• New Demand Period : The PQMII can be used for load shedding by assigning a switch
input to a new demand period. This allows the PQMII demand period to be
synchronized with the utility meter. One of the billing parameters used by a utility is
peak demand. By synchronizing the PQMII to the utility meter, the PQMII can monitor
the demand level read by the utility meter and perform load shedding to prevent the
demand from reaching the penalty level. The utility meter provides a dry contact
output which can be connected to one of the PQMII switch inputs. When the PQMII
senses a contact closure, it starts a new demand period (with Block Interval Demand
calculation only).
• Setpoint Access : The access terminals must be shorted together in order for the
faceplate keypad to have the ability to store new setpoints. Typically the access
terminals are connected to a security keyswitch to allow authorized access only. Serial
port commands to store new setpoints operate even if the access terminals are not
shorted. When the access terminals are open, all actual and setpoint values can still
be accessed for viewing; however, if an attempt is made to store a new setpoint value,
the message
SETPOINT ACCESS DISABLED
is displayed and the previous setpoint
remains intact. In this way, all of the programmed setpoints remain secure and
tamper proof.
• Select Analog Output : This switch selection allows each analog output to be
multiplexed into two outputs. If the switch is active, the parameter assigned in
setpoint
S2 SYSTEM SETUP ÖØ ANALOG OUTPUT 1 ÖØ ANALOG OUTPUT 1 ALT
determines the
output level. If the switch is not active, the parameter assigned in setpoint
S2 SYSTEM
SETUP
ÖØ
ANALOG OUTPUT 1
ÖØ
ANALOG OUTPUT 1 MAIN
is used. See the following section
and 5.3.2: Analog Outputs for additional details.
• Select Analog Input : This switch selection allows the analog input to be multiplexed
into two inputs. If the switch is active, the parameter assigned in setpoint
S2 SYSTEM
SETUP ÖØ ANALOG INPUT ÖØ ANALOG INPUT ALT
is used to scale the input. If the switch is not
active, the parameter assigned in setpoint
S2 SYSTEM SETUP ÖØ ANALOG INPUT ÖØ ANALOG
INPUT MAIN
is used. If a relay is assigned in
S2 SYSTEM SETUP ÖØ ANALOG INPUT ÖØ ANALOG IN
MAIN/ALT SELECT RELAY
, that relay energizes when the switch is active and de-energizes
when the switch is not active, thus providing the ability to feed in analog inputs from
two separate sources as shown in the figure below. See the
2.2.10: Analog Input
(Optional) section below for details. Refer to 5.3.3: Analog Input for additional details.