SATEC PM296 - Manual (Page 30)

Chapter 4 Setup Menus 22
Code Parameter Options Description
rEc.C The number of
cycles in a waveform
series 0 to 2560
(0*) The total number of waveform cycles to be
recorded on either event occurrence. Will be
rounded to a nearest bigger number multiple of
16.
0 = auto-select
Freq Nominal frequency 50, 60 Hz** The nominal line frequency
LoAd Maximum demand
load current 0-10,000A
(0
∗)
The maximum demand load current used in
TDD calculations (0 = CT primary current)
** 60 Hz default for North America; elsewhere, default is 50Hz.
The DC voltage input may be used to measure different analog quantities proportional to
voltage, such as temperature. The DC Voltage reading can be scaled in order to show
the primary parameter quantity by applying zero and full scale offsets to the measured
voltage. To get true DC voltage readings, set the offset to zero and the full scale to 20,
100 or 300 VDC according to your order.
The thermal demand time constant is calculated using the following formula:
) t %( S 100
100
ln
t
−
= τ
where
τ - thermal time constant, sec;
t = demand interval, sec (demand period x number of demand periods);
S%(t) - the level that the thermal demand pointer will attain at the end of the
demand interval, expressed in percentage of the steady-state value.
In meters with S%(t) = 63%, τ = t. For example, using a 15-min demand interval, τ = 900
sec, and with a 30-minute interval - τ = 1800 sec.
In meters with S%(t) = 99%, using a 15-min demand interval, τ = 195.4 sec, and with a
30-minute interval τ = 390.9 sec.
The waveform recorder logs waveforms in series of records. A compound waveform can
have as more as 2560 cycles recorded in 160 consequent records, each record
comprising 16 waveform cycles. When the number of cycles is defined as zero, the
instrument automatically selects the size of a waveform series. By default, a waveform
series is assumed to consist of a single 16-cycle record. When a record is triggered by a
voltage disturbance event and the disturbance lasts for more time than a 16-cycle
record can include, the disturbance event is assumed to be a single long-duration event.
In that case, the recorder will continue storing a waveform in the following adjacent
records while the voltage wave shape is still non-stationary. The total number of records
in a compound waveform will be limited only by the allocated memory.
NOTES
1) The maximum value for CT PRIMARY CURRENT × PT RATIO is 10,000,000. If this
product is greater, power related values will be zeroed.
2) Always specify WIRING MODE, PT RATIO and CT PRIMARY CURRENT prior to
setting up alarm setpoints and analog output channels, otherwise the alarm/event
setpoints and analog outputs which use these parameters will automatically be
disabled.