Utility Solutions XFMR-3BUSHING User manual

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Load-Trainer
Transformer Simulator
XFMR-3BUSHING Three Bushing Transformer Simulator
C-00879 XFMR-3BUSHING (11-11-15)
Operation Manual
Product Description 2
Components 3
Set-Up 4
Simulator Description 4
Front Panel Description 5
Toggle Switches 6
Operation 8
Examples 8
Vector Application 19
Transformer Backfeed 19
Parallel Phases 19
Polarity 19
Polarity Example 20
Warranty 20
CONTENTS
Copyright © 2014 Utility Solutions, Inc.

2
C-00879 XFMR-3BUSHING (11-11-15)
Product Description
The LOAD-TRAINER Transformer Simulator is a fully functional electrical trainer allowing simulation
of most distribution transformer connection schemes. This device contains actual transformers that
completely duplicate in-eld situations.
The power unit’s components are not rated for continuous duty and may heat up during prolonged
use.
The power unit should not be on for extended periods of time and should only be on when
taking voltage readings.
In addition to reduce the risk of electrical shocks, re, etc.:
• Do not remove screws, covers or cabinet. Refer servicing to qualied
personnel.
• Do not expose this device to rain, moisture or combustible materials.
• Select a place that is level, dry and between 41°F and 95°F. Do not place either
unit on a heat generating object.
• Avoid a dusty place or a place subject to vibrations.
• The power cord supplied is congured and rated for standard 120 Volt,
10 Amp receptacles. It is to be used as a disconnect for this device by
unplugging the power cord from the receptacle.
! !
WARNING
Carefully read and fully understand this manual prior to
operating, maintaining or testing this device. Improper
operation, handling or maintenance of this device can result
in death, grievous personal injury and or equipment damage.
! !
WARNING
is unit can exceed 400 volts in certain congurations. Use caution
and treat ALL components and jumpers as if handling live conductors.
! !
WARNING
e unit should NOT be running during hook-up or conguration.

3
C-00879 XFMR-3BUSHING (11-11-15)
Components
Product Line
XFMR-3BUSHING LOAD-TRAINER THREE BUSHING TRANSFORMER SIMULATOR
XFMR-4BUSHING LOAD-TRAINER FOUR BUSHING TRANSFORMER SIMULATOR
XFMR-PRM PHASE ROTATION METER
XFMR-LEADS ASSORTMENT OF EXTRA BANANA LEADS
XFMR-3BUSHING-PRL ADDITIONAL THREE BUSHING FRONT PANEL
XFMR-4BUSHING-PRL ADDITIONAL FOUR BUSHING FRONT PANEL
Front PanelPower Supply
Multiple-conductor
Cord
Shipping Cases
Power Cord
Patch Cords
Qty Description
1 Front Panel (Large Shipping Case)
1 Power Supply (Small Shipping Case)
1 Multiple-conductor cord with polarized plug (Green)
1 120 Volt, AC Power Cord (Black)
812” red ‘pin’ patch cords
312” black ‘pin’ patch cords
44” black ‘banana’ patch cords
512” red ‘banana’ patch cords
512” black ‘banana’ patch cords

4
C-00879 XFMR-3BUSHING (11-11-15)
Simulator Description
Simulation of Three-Phase power is created by an electric motor and a 120-to-20 Volt transformer.
The motor is coupled to an alternator that provides a three-phase, four-wire output. The 20 Volt output
of the transformer is rectied and used to excite the rotor of the alternator. A rheostat on the Front
Panel provides ne tuning over the output of the alternator. When the rheostat knob is pointed toward
the word ‘DELTA’ the output voltage of the alternator is approximately seven (7) Volts phase-to-phase
(VPP). When the knob points to ‘WYE’ the output voltage is approximately seven (7) Volts phase-to-
neutral (VPN). See Equation below.
WYE = VPP = √3 • VPN = DELTA
Hence: WYE = VPP = √3 • 7 Volts
WYE = VPP ≈ 12 Volts
It is for this reason that a Delta connected primary wired to a WYE system voltage can produce
secondary voltages much higher than expected. In addition it may be necessary to ne-tune the
rheostat occasionally to obtain the desired voltage output from the transformers.
Set-Up
The Load-Trainer requires two components to operate; the Front Panel (located in
the large shipping case) and the Power Supply (located in the small shipping case).
The Front Panel may be removed from its shipping case and set on a desk or table
using the built-in easel. The Power Supply remains in its shipping case and will be
connected both to the Front Panel and to an electrical wall outlet.
Check that the protective panel on the power supply is in place and the screws are
securely fastened. This Power Supply case should be clear of all other items and
lying at on a level surface with the lid off for adequate ventilation.
PLEASE NOTE - The 120 volts are REAL and NOT simulated. You must use
caution whenever the unit is on. Never leave the unit on while unattended!
The unit should be on when measuring voltages and NEVER while removing
or installing patch cords. Components could OVERHEAT if left on for
extended periods a time!
1. Verify the “ON-OFF” switch on the Front Panel is in the “OFF” position.
1. Connect the green Multiple-conductor Cord to the Front Panel on the lower left hand corner. Turn
the threaded collar on the plug clockwise a single turn to secure it to the polarized receptacle.
2. Attach the black Power Cord to the Power Supply using the female end. Plug in the Power Cord to
a grounded AC outlet.
! !
WARNING
Never leave the unit unattended while plugged in.
Always remove the black power cord when not in use.

5
C-00879 XFMR-3BUSHING (11-11-15)
Front Panel Description
Three Phase Power System
The four lines at the top of the Front Panel represent a three-phase four-wire power system (A, B, C, N).
The tip jacks located on the lines are connected to buss bars within the panel and are protected by fast
acting thermal circuit breakers and disconnecting switches. The tip jacks are used to make connections
from the three-phase four-wire power system supply to the primaries of single-phase transformers.
Indicator Lights
An indicator light is to the right of each three-phase power line at the top of the Front Panel. This light
will indicate when the line is energized.
Disconnecting Switches
Each three-phase power line has a toggle switch to the right of the indicator light on the Front Panel.
Power can be controlled to each line separately.
Circuit Breakers
Fast acting thermal circuit breakers are included on each of the three-phase power lines at the top of
the Front Panel and function as fuses for accurate simulations. Simply press the circuit breaker to reset.
Transformer Inputs
Three transformer outlines in the middle of the Front Panel use red input terminals (H1 and H2) which
connect to actual transformers located behind the panel. These connections are made using the Pin
Patch Cords (small metal ends). The plugs can be stacked, if desired.
Transformer Outputs
Each transformer has three black unlabeled output terminals. They can be thought of as X1, X2 and X3
from right to left respectively, where X2 is neutral in a 120/240 Volt transformer.
Load Lines
The lines at the bottom of the Front Panel represent load lines (N, L1, L2, L3). Connections between the
transformer output terminals and the load lines are made using the Banana Patch Cords (large metal
ends). These can be stacked if desired.
AC Meter
An AC meter is on the lower right of the Front Panel and is used to measure the transformer’s output.
Tip jacks utilize Banana Patch Cords connected through the load lines or directly to a transformer.
Delta - Wye Rheostat Knob
A rheostat on the Front Panel provides ne tuning over the output of the alternator. It may be necessary
to ne-tune the rheostat to obtain the desired voltage output from the transformers. During Delta
conguration, the knob should be pointed to the left; while in Wye congurations the knob should be
pointing to the right. See Simulator Description for more information.

6
C-00879 XFMR-3BUSHING (11-11-15)
The eight (8) Toggle Switches located on the left side of the Front Panel can be used by instructors to
simulate real-world scenarios that a student would have to diagnose.
The switches are labeled S1 through S8. The normal position of all switches is UP, toward the top of the unit.
Toggle Switches
Switch Description Transformer TOGGLE POSITION
UP MIDDLE DOWN
S1 Phase
Paralleling
Switch
A-B-C B-B-C*
S2 A-B-C A-B-B*
S3 Transformer
Ouput 1120 v (X3↔X2)
No Output (X2↔X1)
Open
(secondary)
120 v (X3↔X2, X2↔X1)
240 v (X3↔X1)
S4 Polarity
Switch 1Additive Subtractive
S5 Transformer
Ouput 2120 v (X3↔X2)
No Output (X2↔X1)
Open
(secondary)
120 v (X3↔X2, X2↔X1)
240 v (X3↔X1)
S6 Polarity
Switch 2Additive Subtractive
S7 Transformer
Ouput 3120 v (X3↔X2)
No Output (X2↔X1)
Open
(secondary)
120 v (X3↔X2, X2↔X1)
240 v (X3↔X1)
S8 Polarity
Switch 3 Additive Subtractive
*when both S1 & S2 are down phasing is B-B-B
H1H2
UP
(additive)
DOWN
(subtractive)
Polarity Switches
(S4/S6/S8)
H1H2
MIDDLE
H1H2
UP
Output Switches
(S3/S5/S7)
DOWN
H1H2
X1X2X3 X3X2X1
H1H2
X3X2X1X3X2X1X3X2X1

7
C-00879 XFMR-3BUSHING (11-11-15)
Front Panel
Top of Unit
UP - ABC
DN - BBC
Transformer #1
UP – 120 X1-X2
CTR - 0
DN – 240 X1-X3
Transformer #2
UP – 120 X1-X2
CTR - 0
DN – 240 X1-X3
Transformer #3
UP – 120 X1-X2
CTR - 0
DN – 240 X1-X3
UP - ABC
DN - ABB
(S1 & S2 Both DN - BBB)
Transformer #1
UP - Additive Polarity
DN - Subtractive Polarity
Transformer #2
UP - Additive Polarity
DN - Subtractive Polarity
Transformer #3
UP - Additive Polarity
DN - Subtractive Polarity
Normal position of all switches is UP, toward the top of the unit.
Left Side of Front Panel
FIGURE 1: Toggle Switches
S2 S4 S6 S8 S1 S3 S5 S7

8
C-00879 XFMR-3BUSHING (11-11-15)
Operation
The Load-Trainer Transformer Simulator has the capability to connect single-phase and the following
types of three-phase transformers:
Simple Single-Phase Transformer Connections
1. The system should be OFF and remain OFF except for observing voltage measurements on the AC
meter for short periods of time.
2. Be sure all 8 Toggle Switches are in the UP position for normal operation. Be sure all 3 Disconnecting
Switches are ‘ON’ and reset any tripped Circuit Breakers.
3. Using the red ‘pin’ tip patch cords connect a single-phase transformer to a DELTA system primary
as shown in Example 1.
4. Set rheostat pointer to ‘DELTA’.
5. Make output connections with the red and black banana patch cords bringing leads down to load
lines to a 120 Volt WYE secondary as shown in Example 1.
6. Turn the unit ON. The Power Supply will start and deliver the proper voltage to the transformer.
NOTE: The power unit should not be operated for extended periods of time. Run only when
taking voltage readings.
7. If connections have been properly made voltage should appear on the AC Meter. These readings
should be near normal for the transformer bank being made. Use the rheostat to make minor
adjustments.
8. Problems can be introduced after the installation has been shown to operate correctly. This is
done by the toggle switches on the left side of the Front Panel (see Figure 1) and at the instructors
discretion to simulate real world scenarios.
NOTE:
In certain congurations the actual measured device output voltage is greater than or less than the
expected voltage for a given simulation. The AC Meter has been scaled at the factory to compensate for
the differing output voltages. An independent meter device may display voltages that are not expected.
Delta-Delta
Delta-Wye
Open Delta-Open Delta
Wye-Delta
Wye-Wye
Wye (one leg out)-Open Delta
Examples
The following table summarizes the Connection Diagrams provided on the following pages:
Example Simulation
1 Single Phase Transformer w/ Delta Primary & 120 Volt Wye Secondary
2 Single Phase Transformer w/ Delta Primary & 120 Volt Delta Secondary
3 Single Phase Transformer w/ Delta Primary & 120/ 240 Volt Delta Secondary
4 Three Phase Transformer w/ Delta Primary & 120 / 208 Volt Wye Secondary
5 Three Phase Transformer w/ Delta Primary & 120 Volt Delta Secondary
6 Three Phase Transformer w/ Delta Primary & 120 / 240 Volt High Leg B Delta Secondary
7 Three Phase Transformer w/ Open Delta Primary & 120 Volt Open Delta Secondary
8 Three Phase Transformer w/ Wye Primary & 120 Volt Delta Secondary
9 Three Phase Transformer w/ Wye Primary & 120 / 208 Volt Wye Secondary
10 Three Phase Transformer w/ Wye (One Leg Out) & 120 Volt Open Delta Secondary

9
C-00879
(7-15-14)
Single Phase Transformer with Delta Primary
and 120 Volt Wye Secondary
Example 1
Toggle Switches: All in the UP Position
Rheostat Knob: Delta
Expected Meter Reading
Phase to Ground: 120 volts
Phase to Phase: 0 volts (not shown)
S2 S4 S6 S8
S1 S3 S5 S7

10
C-00879
(7-15-14)
Single Phase Transformer with Delta Primary
and 120 Volt Delta Secondary
Example 2
Toggle Switches: All in the UP Position
Rheostat Knob: Delta
Expected Meter Reading
Phase to Ground: 0 volts (not shown)
Phase to Phase: 120 volts
S2 S4 S6 S8
S1 S3 S5 S7