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CET Electric Technology
4.2.3 Demands
Demand is defined as the average power consumption over a fixed interval (usually 15 minutes). The
PMC-592 provides present demand for Mains, SMs and Temperature measurements. In addition, the
PMC-592 records the Max Demand for This Month, Last Month and Historical which are stored in non-
volatile memory and will not suffer any loss in the event of a power failure.
The PMC-592 supports the sliding window demand calculation and has the following setup parameters:
Setup Parameter
Value or Description
# of Sliding Windows
(Reg. # 6012)
1 to 15 (Default = 1)
Demand Period
(Reg. # 6011)
1/2/3/5/10/15*/30/60(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. (Default = 15)
Self-Read Time
(Reg. # 6021)
The
Self-Read Time
allows the user to specify the time and day of the month for the Demand Log
Self-Read operation. At the specified time in each month, the Max Demand of
This Month
is
transferred to the Max Demand of
Last Month
and then reset. The
Self-Read Time
supports two
options:
A zero value means that the Self-Read will take place at 00:00 of the first day of each month.
A non-zero value means that the Self-Read will take place at a specific time and day based on the
formula: Self-Read Time = Day * 100 + Hour where 0 ≤ Hour ≤ 23 and 1 ≤ Day ≤ 28. For example,
the value 1512 means that the Self-Read will take place at 12:00pm on the 15th day of each
month.
(Default=0)
Table 4-7 Demand Setup Parameters
The PMC-592 provides the following Demand and Max Demand parameters:
Demand and Max Demand Parameters
Mains-I Ia
Mains-I Ib
Mains-I Ic
RTD1 Temperature*
Mains-I kW Total
Mains-I kvar Total
Mains-I kVA Total
RTD2 Temperature*
Mains-II Ia
Mains-II Ib
Mains-II Ic
-
Mains-II kW Total
Mains-II kvar Total
Mains-II kVA Total
-
1-Ø SM1 I
1-Ø SM2 I
…
1-Ø SM84 I
2-Ø SM1 I
2-Ø SM2 I
…
2-Ø SM42 I
3-Ø SM1 I
3-Ø SM2 I
…
3-Ø SM28 I
1-Ø SM1 kW
1-Ø SM2 kW
…
1-Ø SM84 kW
2-Ø SM1 kW
2-Ø SM2 kW
…
2-Ø SM42 kW
3-Ø SM1 kW
3-Ø SM2 kW
…
3-Ø SM28 kW
1-Ø SM1 kvar
1-Ø SM2 kvar
…
1-Ø SM84 kvar
2-Ø SM1 kvar
2-Ø SM2 kvar
…
2-Ø SM42 kvar
3-Ø SM1 kvar
3-Ø SM2 kvar
…
3-Ø SM28 kvar
1-Ø SM1 kVA
1-Ø SM2 kVA
…
1-Ø SM84 kVA
2-Ø SM1 kVA
2-Ø SM2 kVA
…
2-Ø SM42 kVA
3-Ø SM1 kVA
3-Ø SM2 kVA
…
3-Ø SM28 kVA
* Available in Firmware V1.00.04 or later
Table 4-8 Demand Parameters
Notes:
1)
The Mains or SMx Max Demands can be reset manually through communications, the built-in Web Interface or the optional
HMI.
4.3 Alarm Setpoints
The PMC-592 provides powerful alarming functions for the Mains and Branch Inputs as well as for
different parameters. Each Alarm Type has an independent enable switch, which allows the alarms for
Mains-I, Mains-II and Branch to be enabled separately as needed. The alarms may also be disabled by
setting the alarm threshold to 0.
4.3.1 Alarm Status
The PMC-592 supports both the
Instantaneous Alarm
and
Latched Alarm
, which are defined below.