CET Electric Technology
11
Chapter 4
Applications
4.1
Inputs and Outputs
4.1.1
Digital Inputs
The PMC-230 comes standard with three self-excited Digital Inputs that are internally wetted at 12VDC. Digital
Inputs on the PMC-230 can be used in the following applications:
1)
Status Input
The digital inputs are typically used for status monitoring which can help prevent
equipment damage, improve maintenance, and track security breaches. The real-time
statuses of the Digital Inputs are available through communications. Changes in
Digital Input status are stored as events in the SOE Log in 1 ms resolution.
2)
Pulse Counting
Pulse counting is supported with programmable debounce and pulse weight to
facilitate WAGES (Water, Air, Gas, Electricity and Steam) information collection.
The following table describes the DI Setup Parameters that can be programmed over communications:
Setup Parameter
Definition
Options/Default*
DIx Function
Each
DI
can be configured as a Status Input or Pulse Counter.
0=Status Input
1=Pulse Counter*
DIx Debounce
Specifies the minimum duration the
DI
must remain in the Active
or Inactive state before a DI state change is considered to be valid.
1 to 9999 (ms)
20ms*
DIx Pulse Weight
Specifies the incremental value for each received pulse. This is only
used when a DI is configured as a Pulse Counter.
1* to 1,000,000
Table 4-1 Digital Input Setup
4.1.2
Energy Pulse / 1 PPS Output
The PMC-230 comes standard with one Front Panel LED Pulse Output and one Solid State Relay Output for kWh
or kvarh Energy Pulsing. Energy Pulse Output is typically used for accuracy testing. Energy Pulsing is enabled by
default and can be disabled from the Front Panel or through communications. The Pulse Constant is fixed at 1000
impulses per kWh or kvarh. If the
DO Energy Pulsing
(
do
) parameter is disabled, the PMC-230 will output a 1PPS
signal with a pulse width of 500ms ± 0.5ms at the Energy Pulse Output terminals (
E+
,
E-
) for the accuracy testing
of its internal clock.
4.1.3
Disconnect Relay
The PMC-230 comes standard with one internal Disconnect Relay which can be manually operated via the Front
Panel or remotely controlled via communications to switch the load off or back on.
4.2
Metering
4.2.1
Basic Measurements
The PMC-230 provides real time measurements for I, U, P, Q, S, PF, Freq., U THD, I THD and Operating Time.
4.2.2
Energy Measurements
The PMC-230 provides Energy measurements for kWh, kvarh Import/Export and kVAh at a resolution of 0.01 kxh
and a maximum value of 1,000,000.00 kxh. When the maximum value is reached, it will automatically roll over
to zero. The energy measurements can be reset manually via the Front Panel or through communications as well
as preset via communications.
4.2.3
Demands
Demand is defined as the average consumption over a fixed interval (usually 15 minutes) based on the sliding
window method. The PMC-230 provides the Present Demand, Max. Demand for This Month (Since Last Reset)
and Last Month (Before Last Reset) for I, U, P, Q and S. The Present Demand and Max. Demand measurements
can be retrieved via communications, and its Setup Parameters can be configured via the Front Panel (except for
the
Self-Read Time
parameter) and through communications.
The PMC-230 provides the following Demand Setup parameters:
Parameter
Definition
Options/Default*
Period
1 to 60 minutes. For example, if the
# of Sliding Windows
is set as 1 and
the
Demand Period
is 15, the demand cycle will be 1×15=15min.
1 to 60 minutes,
5*
# of Sliding
Windows
Number of Sliding Windows.
1 to 15, 1*