Power calculation modes – SATEC EM720 Operation Manual User Manual

Page 71

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Chapter 5 Configuring the EM720

General Meter Setup

EM720 Power Quality and Revenue Meter

71

Display

Label

Parameter Options Default

Description

Power/Energy Options

Power Mode

Power
Calculation

Mode

S=f(P, Q) (reactive
power mode),
Q=f(S, P) (non-
active power

mode)

S=f(P, Q)

The method used for calculating
reactive and apparent powers (see

“Power Calculation Modes” below)

Energy Roll

Energy Roll
Value, kWh

1000.0
10000.0
100000.0
1000000.0
10000000.0
100000000.0

100000000.0 The value at which energy

counters roll over to zero

End of Bill

End of Billing
Period

Auto (monthly)
Auto/COM
Auto/COM/Manual
COM
Manual

Auto
(monthly)

Triggering an end of billing period:
Auto – monthly self-reading
COM – remote via communications
Manual – from the front display

Trf Control

Tariff Control Calendar

Communication
Tariff inputs

D1…D8

1

Defines the tariff switching method
(see “Tariff Control” below).

Num Tariffs

Number of
tariffs

1-8

1

Defines the number of season tariff
rates when no TOU calendar

schedule is available

Trans. Corr.

OFF (disabled)
ON (enabled)

OFF

Enables instrument transformer
correction – only via the front

display

Loss Comp.

OFF (disabled)
ON (enabled)

OFF

Enables transformer/line loss
compensation – only via the front

display

Test Mode

Test Mode

Energy LED

Test

OFF (disabled)
ON (enabled)

Disabled

Setting this option puts the meter

into TEST mode

Pulse Const

Energy LED
pulse rate,

Wh/impulse

0.01-0.25 Wh/imp
(100,000 – 4,000
imp/kWh)

0.10 Wh/imp
(10,000

imp/kWh)

Test LED pulse constant - the
amount of accumulated energy (in
secondary units) giving one pulse

via “kWh” and “kvarh” LEDs.

Data Scales

N/A

Volts Scale, V 60-600 V

144 V

The maximum voltage scale
allowed, in secondary volts. See

Data Scales

in Appendix F

N/A

Amps Scale, A 1.0 – 50.0

2A/10 A

The maximum current scale
allowed, in secondary amps. See

Data Scales

in Appendix F

Power Calculation Modes

The power calculation mode option allows you to change the
method for calculating reactive and apparent powers in
presence of high harmonics. The options work as follows:

1. When the reactive power calculation mode is selected,

active and reactive powers are directly measured and
apparent power is calculated as:

2

2

Q

P

S

+

=

2. This mode is recommended for electrical networks with

low harmonic distortion, commonly with THD < 5% for

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