weschler instruments Power Series Plus User manual

IM2493VAF-3
POWER SERIES Plus
Volt / Amp / Hertz
Digital Switchboard Meter
User’s Manual

1
IM2493VAF-3
General Description
The POWER SERIES Plus digital switchboard meters incorporate the latest DSP
microprocessor technology. Careful and thoughtful design has resulted in a family of user-
friendly, field-adjustable meters.
When ordering the 2493 meter, the following options are available:
•AC Measuring Function(s): Volts, Amps, Watts, VARs, Power Factor, and/or
Frequency.
•Input Range: 0-150, 0-300V, 0-600V, 0-1 A, 0-5 A, 40-70 Hz, 300-500 Hz
•Wiring Configuration: 1P2W, 1P3W, 3P3W, 3P4W, 3P4W 2½ element
•Analog Output Type: 0 to 1mADC, 4 to 20 mADC, or none
•Power Supply: Universal Power Supply (85VAC-265VAC/110VDC-340VDC),
24VDC, or 48VDC.
•Communications: MODBUS comm., ASCII protocol or no comm.
The meter display and output scaling are completely field-adjustable from the front panel.
The meter does not need to be re-calibrated after adjusting the display or the output scaling.
There are no internal parts that the user needs to service or adjust. When a POWER SERIES
Plus meter leaves the factory it will be calibrated to meet or exceed its published specifications.
SAFETY NOTE: There are no field-serviceable parts in the unit. If the unit is
disassembled for any reason both Auxiliary Power and input voltages and currents must be de-
energized. LIMITED WARRANTY
This meter has been delivered to you after strict quality control and inspection. Weschler
Instruments warrants its Equipment to meet applicable specifications and to be free from defects
in material and workmanship for a period of one (1) year from date of shipment to the original
Purchaser. Upon receipt of prompt notice from Purchaser, referencing the order number and
detailing the claimed non-conformity or defect, Seller shall, at its option, repair or replace the
Equipment. Equipment returned to Seller will only be accepted with a Returned Material
Authorization (RMA) number issued by Seller or one of its authorized representatives. Inbound
shipping charges to Seller’s factory in Cleveland OH, or other designated facility, are the
responsibility of Purchaser. Normal shipping charges for the return to Purchaser of repaired or
replacement Equipment shall be the responsibility of the Seller (North American points only).
Repair or replacement of the Equipment in the manner described above is the exclusive
warranty remedy and shall constitute complete fulfillment of all Seller’s liabilities for breach of
this warranty. The Seller assumes no responsibility hereunder for any equipment damage or
failure caused by improper installation, operation and maintenance of the Equipment, or normal
wear and tear on disposable or consumable parts. This warranty shall be void in the event of
unauthorized modification or servicing of the Equipment.
The foregoing warranty is exclusive and in lieu of any other warranties of quality,
whether expressed or implied (including any warranty of merchantability or fitness for a
particular purpose). In no event shall Seller be liable hereunder for any special, indirect,
incidental or consequential damages including the loss of revenue or production.

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IM2493VAF-3
Volt / Amp / Hertz Specifications
PRODUCT FUNCTION: AC Volts, 1 Phase or 3 Phases, 3 Wires or 4 Wires
AC Amps, 1 Phase or 3 Phases
Frequency
ACCURACY: ±0.2% of Reading ±0.1% of Full Scale
DISPLAY UPDATE RATE: 250 milliseconds
OPERATING TEMPERATURE RANGE: -20 to +60 °Celsius
STORAGE TEMPERATURE RANGE: -40 to +85 °Celsius
INPUT RANGES: 0-150 VAC or 0-300 VAC or 0-600 VAC
(except 3 phase, 3 wire)
0-120 VAC or 0-240 VAC or 0-480 VAC
(3 phase, 3 wire only)
0-1 Amp AC or 0-5 Amps AC
40-70 Hertz or 300-500 Hertz
TRANSFORMER RATIO RANGES:
Potential Transformer: 1:1 through 9999:1
Current Transformer: 1:1 through 9999:1
ANALOG OUTPUTS (Optional): 0 – 1 mADC, 10 VDC compliance into 10 kΩ
4 – 20 mADC, 15 VDC compliance into 750 Ω
ANALOG OUTPUT RESPONSE TIME: Within ±1% of final value within 1 second
ISOLATION:
Input/Output and Case: 2500 VAC
Output to Aux. Power: 2000 VAC or 500 VDC for DC powered option
Aux. Power to Case: 2000 VAC or 500 VDC for DC powered option
Output to Case: 1000 VAC

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IM2493VAF-3
CONFIGURING THE 2493 POWER SERIES Plus METER
The new triple-display POWER SERIES Plus can be configured for voltage and current
inputs from instrument transformers, as well as analog outputs, Modbus or ASCII protocol
Communications parameters and a rolling average display.
All set-up functions can be performed using the four push-buttons on the front panel (see
below) or via ASCII or Modbus communications. You can also use the buttons to display the
minimum and maximum readings and to change the display from phase to phase.
This button starts all
operations.
When viewing or
changing settings it
is used to back out
of a mode.
This button can
change the phase
being displayed, or,
when viewing or
changing settings, it
moves between
settings or between
digits.
This button will
increment the value
being changed.
It is also used to
display Max
readings.
This button, when
viewing or changing
settings, is used to
select a mode, save
it, and then move to
the next mode in the
sequence.
It is also used to
display Min
readings.
All button operations are begun with the Mode button.
To see the Min or Max, push the Mode button and then the button of the reading you
want to see – Min or Max. The values will display for ten (10) seconds before reverting to the
normal display. If you want to reset the values, push the Min or Max button again before the 10
seconds has expired.
To change between phases, press the Mode button first, and then the Next button. The
display will change phases in the following order: A-B-C-AB-BC-CA and back to A. The
LEDs at the top of the unit will show the current phase being displayed. The solid light shows
the Amps phase. If there is no blinking light, the Voltage being displayed is line-to-neutral. If
there is a blinking light then the voltage is line-to-line. A unit with 3 Phase 3 Wire connection
will not display line-to-neutral values. The frequency displayed is always a measurement of
Phase A.
To view the configuration settings, press Mode twice (Mode – Mode) and then press Set.
The first setting – the Primary Transformer (PT) ratio - will be displayed.. To see the other
settings, press Next. You can scroll through all the settings by pressing Next. To go back to
normal operations, press Mode. To change the setting being shown, press Set. See the specific
sections on the following pages for details on how to change the settings. Once a setting is
changed it will advance to the next setting. At any point while changing settings, pressing Mode
will exit the mode without changing anything.

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IM2493VAF-3
KEY MAP
This flowchart illustrates the operation of the POWER SERIES Plus meter using the
push-keys on the front panel.

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IM2493VAF-3

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IM2493VAF-3
CHANGING THE POTENTIAL TRANSFORMER (PT) RATIO SETTING
When you reach the PT setting the primary value is shown in the middle row and the
secondary value in the bottom row. Press Set and the first digit of the primary value will begin
blinking. You can increment the value of this digit by pressing Inc. Once a digit has reached 9
(nine) it will then go to 0 (zero). To move to the next digit press Next. You can return to the
first digit by pressing Next while the last digit is blinking.
When you have the digits as you want them, press Set. The decimal point will now be
blinking. You can then move the decimal point to the right by pressing Inc. Once it has
reached the last position it will jump to the first position on the next Inc.
Pressing Set again will bring you to the Multiplier (Kilo) setting. In the leftmost digit
you will see a blinking ‘ |- ‘ and if the multiplier light is on it will also blink. You can change the
setting by pressing Inc.
The next time you press Set the value of the secondary will blink. To change the value,
press Inc. There are only two choices: 1 or 120. (1 or 240 if the input range is 0-300V).
Pressing Set will now move you to the Confirm mode. All values will blink. If the
values are correct press Set one last time to save them and move on to the Current Transformer
settings. Pressing Mode at this time or at any other step in the process will restore the old PT
settings.
The PT primary value can be set to any value between 1.000 and 4799520(480Volts X
9999 ratio). If it is not in this range you get the error “ErrH” (Too High) or “ErrL” (Too Low)
when you try to advance to the secondary. The ratio of the Primary and Secondary must be
between 1.000 and 9999. You will get “ErrH” or ErrL” if you try to advance to Confirm mode
with an incorrect ratio.
If you try to save a ratio value that exceeds the precision of the unit, that value will be
automatically rounded off. For example, setting the PT to a ratio of 12.34k to 120 results in a
value of 102.833333. The unit will round this to 102.8, and in the future display the ratio as
12.33k to 120. Setting the secondary to 1 will always avoid this.

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IM2493VAF-3
CHANGING THE CURRENT TRANSFORMER (CT) RATIO SETTING
When you reach the CT setting, the primary value is shown in the middle row and the
secondary value is in the bottom row. Press Set and the first digit of the primary value will
begin blinking. You can increment the value of this digit by pressing Inc. Once a digit has
reached 9 (nine) it will then go to 0 (zero). To move to the next digit press Next. You can
return to the first digit by pressing Next while the last digit is blinking.
When you have the digits as you want them, press Set. The decimal point will now be
blinking. You can then move the decimal point to the right by pressing Inc. Once it has
reached the last position it will jump to the first position on the next Inc.
Pressing Set again will bring you to the Multiplier (Kilo) setting. In the leftmost digit
you will see a blinking ‘ |- ‘ and if the multiplier light is on, it will also blink. You can change
the setting by pressing Inc.
If you have a 5 Amp unit, the next time you press Set the value of the secondary will
blink. To change the value, press Inc. There are only two choices: 1 or 5.
If you have a 1 Amp unit, or you have set the secondary on a 5 Amp unit, pressing Set
will now move you to the Confirm mode. All values will blink. If the values are correct press
Set one last time to save them and move on to the Analog Output settings. Pressing Mode at
this time or at any other step in the process will restore the old CT settings.
The CT primary value can be set to any value between 1.000 and 49995 (5 Amps X 9999
ratio). If it is not in this range you get the error “ErrH” (Too High) or “ErrL” (Too Low) when
you try to advance to the secondary. The ratio of the Primary and Secondary must be between
1.000 and 5000. You will get “ErrH” or ErrL” if you try to advance to Confirm mode with an
incorrect ratio.
If you try to save a ratio value that exceeds the precision of the unit, that value will be
automatically rounded off. For example, setting the CT to a ratio of 5.367 to 5 results in a value
of 1.0734. The unit will round this to 1.073, and in the future display the ratio as 5.365 to 5.
Setting the secondary to 1 will always avoid this.

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IM2493VAF-3
CHANGING THE ROLLING AVERAGE SETTING
The rolling average causes the displayed value to be an average of the number of samples
to which this parameter is set. Increasing this setting will reduce digit bounce, but will slow the
display response time. The analog output response time is not affected by this setting.
When you reach the Average setting, press Set and the first digit will begin blinking.
To increment the value of the digit, press Inc. Once a digit has reached 9 (nine), it will then go
to 0 (zero). To move to the second digit press Next. To return to the first digit press Next
again. When you have set the desired value, press Set. Both digits will blink, showing you are
now in Confirm mode. If the value is correct press Set one more time to save the value and
move on to the Address setting. Pressing Mode at any time before this will restore the old
setting.
The average can be set to any value from 0 to 29.
CHANGING THE NETWORK ADDRESS SETTING
The Address setting is changed in exactly the same way as the Average setting.
The address can be set to any value from 01 to 32. NOTE – No two units should have the same
address. If this occurs neither will communicate properly.
After saving the value you will move to the Baud Rate setting.
CHANGING THE BAUD RATE SETTING
When you reach the setting, press Set and the whole value will begin blinking.
To change it to the next choice, press Inc. You can scroll through all the choices with the Inc
key. Those choices are 9600 (default), 4800, 2400 and 1200. When you have reached the
desired choice, press Set. The new setting will be saved and the unit will proceed to the next
mode.

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IM2493VAF-3
Analog Output Scaling
The POWER SERIES Plus has the option of analog output, which can provide an analog
signal relative to the input of the meter. The relationship between the input and the output can be
scaled by the user using the front panel. Analog Output 1 is always proportional to the value
shown on the top display (Volts). Output 2 is always proportional to the middle display (Amps),
and Output 3 will always be proportional to the bottom display (Hertz).
A 150V voltmeter with 0 to 1 milliamp output, for example, has the following default settings:
PT ratio: 1 to 1
Analog Output LO: 0 Volts
Analog Output HI: 150 Volts
The LO is the input value at which the output
will be 0 mA. The HI is the input value at which the
output will be 1 mA. The charts at right show the
relationship of input and output.
When the settings are changed to:
PT ratio: 1 to 1
LO: 20 Volts
HI: 120 Volts
The new relationship of input and output is shown at
right.
Next the PT ratio is changed to 2 to 1 (2:1). Note that
the HI and LO for voltage input automatically change
to match the new ratio whenever the PT ratio is
changed. The HI and LO for current input
automatically scale whenever the CT ratio is changed.
The HI and LO for frequency are not affected by PT
and CT.
So now the settings are -
PT ratio: 2 to 1
LO: 40 Volts
HI: 240 Volts
And the relationship is shown at right.
0
30
60
90
120
150
0 0.25 0.5 0.75 1
DC Current Out (mA)
0
30
60
90
120
150
0 0.25 0.5 0.75 1
DC Current Out (mA)
0
60
120
180
240
300
0 0.25 0.5 0.75 1
DC Current Out (mA)