Instruction Manual

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:
22
QPS +=
2. This mode is recommended for electrical networks with
low harmonic distortion, commonly with THD < 5% for