Larson Electronics PDU-ATS-100A-208Y.120-3PH User manual

PDU-ATS-100A-208Y.120-3PH
100-amp Automatic Transfer Switch
208Y/120 3PH - Aluminum - NEMA 3R
Instruction Manual
Thank you for your purchase of the Larson Electronics:
PDU-ATS-100A-208Y.120-3PH, 100-amp Automatic Transfer Switch
WARNING:
READ CAREFULLY BEFORE INSTALLING FIXTURE. RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE.
CRITICAL SAFETY INSTRUCTIONS:
•INSTALLATION SHOULD ONLY BECONDUCTED BY A QUALIFIED ELECTRICIAN IN ACCORDANCE WITH NEC AND ANY
RELEVANT LOCAL BUILDING CODES.
•RISK OFFIRE OR ELECTRIC SHOCK. FIXTURE INSTALLATION REQUIRES KNOWLEDGE OF ELECTRICAL SYSTEMS. IF
NOTQUALIFIED, CONTACT A QUALIFIED ELECTRICIAN.
•BE CERTAIN ELECTRICAL POWER IS OFF BEFORE AND DURING INSTALLATION AND MAINTENANCE.
•MAKE SURE THE SUPPLY VOLTAGE IS THE SAME AS THE RATED FIXTURES VOLTAGE.
•TO PREVENT WIRING DAMAGE OR ABRASION, DO NOT EXPOSE WIRING TO EDGES OF SHEET METAL OR SHARP
OBJECTS. SUITABLE FOR DAMP LOCATIONS.
The standard switch enclosure is a National Electrical Manufacturer’s Association (NEMA) and UL 3R type. UL and NEMA 3R type
enclosures primarily provide a degree of protection against falling rain and sleet; undamaged by the formation of ice on the enclosure.
Before installing, operating or servicing this equip-ment, read the SAFETY RULES (inside front cover) carefully. Comply strictly with all
SAFETY RULES to prevent accidents and/or damage to the equip-ment. The manufacturer recommends a copy of the SAFETY
RULES are made and posted near the trans-fer switch. Also, be sure to read all instructions and information found on tags, labels and
decals affixed to the equipment.
The Larson Electronics PDU-ATS-100A-208Y.120-3PH Automatic Transfer Switch is ideal for managing electrical loads between two
sources in industrial facilities. This 100-amp, 208Y/120 three-phase controller handles timing, sensing, exercise functions and transfer
commands. Constructed of aluminum, the unit is housed in a NEMA 3R enclosure.
MOUNTING
PDU-ATS-100A-208Y.120-3PH are wall-mounted or surface-mounted. Install the transfer switch as close as possible to
the electrical loads that are to be connected to it. Mount the switch vertically to a rigid supporting structure. To prevent
switch distortion, level all mounting points. If necessary, use washers behind mounting holes to level the unit.
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3-POLE-MECHANISM
These switches (Figure 1) are used with a three phase system,
when the three phase NEUTRAL line is to be connected to a
NEUTRAL lug and is not to be switched.
Solderless, screw-type terminal lugs are standard.
The conductor size range is as follows:
Switch Rating Wire Range
100 A #6-2/0 AWG
200A #4-400 MCM
Conductor sizes must be adequate to handle the max-imum current to
which they will be subjected; based on the 75°C column of tables,
charts, etc. used to size conductors. The installation must comply fully
with all applicable codes, standards and regulations.

Connect power source load conductors to clearly marked transfer mechanism terminal lugs as fol-lows
1. Connect UTILITY (NORMAL) power source cables to switch terminals N1, N2, N3.
2. Connect EMERGENCY (STANDBY) source power cables to transfer switch terminals E1, E2, E3.
3. Connect customer LOAD leads to switch termi-nals T1, T2, T3.
4. Connect neutral conductors of UTILITY, EMERGENCY and customer LOAD to the neutral block.
Conductors must be properly supported, of approved insulative qualities, protected by approved conduit, and of the
correct wire gauge size in accordance with applicable codes.
Be sure to maintain proper electrical clearance between live metal parts and grounded metal. Allow at least
1/2 inch for 100-400 amp circuits.
CONNECTING START CIRCUIT WIRES
Control system interconnections consist of UTILITY 1 and 2, and leads 23 and 194. Control system interconnection leads
must be run in a conduit that is separate from the AC power lead. Recommended wire gauge sizes for this wiring
depends on the length of the wire, as recommended below:
MAXIMUM WIRE LENGTH RECOMMENDED WIRE
SIZE
460 feet (140m) No. 18 AWG.
461 to 730 feet (223m) No. 16 AWG.
731 to 1,160 feet (354m) No. 14 AWG.
1,161 to 1,850 feet (565m) No. 12 AWG.
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POWER
•PDU-ATS-100A-208Y.120-3PH is compatible with input voltages of 208Y/120 3PH.
•Power source and load connec-tions are made at a transfer mechanism, inside the switch enclosure.
Before connecting wiring cables to terminals, remove any surface oxides from the cable ends with a wire brush. All power
cables should enter the switch next to transfer mechanism terminals. If ALUMINUM con-ductors are used, apply corrosion
inhibitor to con-ductors. Tighten terminal lugs to the torque values as noted on the decal located on the inside of the door.
After tightening terminal lugs, carefully wipe away any excess corrosion inhibitor.
All power cables should enter the switch next to the transfer mechanism terminals.
AUXILIARY CONTACTS
If desired, there are Auxiliary Contacts on the transfer switch to
operate customer accessories, remote advi-sory lights, or remote
annunciator devices. A suitable power source must be connected to
the COMMON (C) terminal. See Figure 2.
Contact operation is shown in the following chart:
Switch Position
Utility Standby
Common to Normally Open Open Closed
Common to Normally Closed Closed Open
Optional
Auxiliary Contact
(Actuated)
Side views shown in Utility position
NOTE:
Auxiliary Contacts are rated 10 amps at 125 or
250 volts AC. DO NOT EXCEED THE RATED
VOLTAGE AND CURRENT OF THE CONTACTS.

MANUAL OPERATION
A manual HANDLE is shipped with the transfer switch. Manual operation must be checked BEFORE the transfer switch is
operated electrically. To check manual operation, proceed as follows:
1. Turn the generator’s AUTO/OFF/MANUAL switch to OFF.
2. Turn OFF both UTILITY and EMERGENCY power supplies to the transfer switch, with whatever means provided
(such as the main line circuit breakers).
3. Note position of transfer mechanism main contacts by observing the display windows, "UTILITY" and "STANDBY",
as follows:
o"UTILITY" window ON, "STANDBY" window OFF - LOAD termi-nals (T1, T2, T3) are connected to utility
termi-nals (N1, N2, N3).
o"UTILITY" window “A” OFF, "STANDBY" window ON - LOAD termi-nals (T1, T2, T3) are connected to
emergency terminals (E1, E2, E3).
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PDU-ATS-100A-208Y.120-3PH
CLOSE TO NORMAL SOURCE SIDE
Before proceeding, verify the position of the switch by observing THE "UTILITY" window. If window reads “ON”, the
contacts are closed in the normal position, no further action is required. If it reads “OFF”, proceed with Step 1.
Step 1: With the handle attached to the actuating shaft, move handle in the direction of the arrow on the switch cover until
it stops — DO NOT FORCE. Release handle slowly to allow the spring in the switch box to relax. “ON” now appears in the
"UTILITY" window and “OFF” appears in the "STANDBY" window.

UTILITY VOLTAGE CHECKS
1. Turn ON the UTILITY power supply to the transfer switch with whatever means provided (such as the UTILITY main
line circuit breaker).
2. With an accurate AC voltmeter, check for correct voltage.
Measure across ATS terminal lugs N1 to N2, N2 to N3, and N1 to N3.
Measure across ATS terminal lugs N1 to NEUTRAL, N2 to NEUTRAL, and N3 to NEUTRAL.
3. Locate the 3 phase power monitor relay. Verify the following:
208 Vac system - LED green and ON
480 Vac system - LED - NORM indicator (green ON)
The factory setting is 80% of nominal voltage (208 Vac systems = 166 Vac dropout)
(480 Vac systems = 384 Vac dropout)
4. If the LED indicator is not ON, then it will be necessary to adjust the power monitor relay setting. Rotate the
adjustment potentiometer in a counter-clockwise direction until the LED turns ON. At this point the 3 phase power
monitor relay is the most sensitive to irregular power line conditions.
5. When certain that UTILITY supply voltage is cor-rect and compatible with transfer switch ratings, turn OFF the
UTILITY supply to the transfer switch.
GENERATOR VOLTAGE CHECKS
1. On the generator panel, set the AUTO/OFF/MANUAL switch to MANUAL position. The gen-erator should crank and
start.
2. Let the generator stabilize and warm up at no-load for at least five minutes.
3. Set the generator's main circuit breaker (CB1) to its ON or CLOSED position.
4. With an accurate AC voltmeter and frequency meter, check the no-load, voltage and frequency. Measure across ATS
terminal lugs E1 to E2, E2 to E3 and E1 to E3.
Measure across ATS terminal lugs E1 to NEUTRAL, E2 to NEUTRAL and E3 to NEUTRAL.
a. Frequency ....................................... 60-62 Hz
b. Terminals E1-E2, E2-E3, E1-E3 ..... 208-212VAC or 470-485
c. Terminals E1-N, E2-N, E3-N ........... 120-122VAC or 272-282
d. It will also be necessary to verify that the phase rotation of the utility matches the phase rotation of the
generator. This can be done by using a phase rotation indicator
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CLOSE TO EMERGENCY SOURCE SIDE
Before proceeding, verify the position of the switch by observing the "STANDBY" window. If the "STANDBY" window reads
“ON”, the contacts are closed in the EMERGENCY (STANDBY) position. No further action is required. If it reads “OFF”,
proceed with Step 1.
Step 1: With the handle attached to the actuating shaft, move the handle in the direction of the arrow on the switch cover
until it stops - DO NOT FORCE. Release handle slowly to allow the spring in the switch box to relax. “OFF” now appears in
the "UTILITY" window and “ON” appears in the "STANDBY" window.
5. When certain that UTILITY supply voltage is cor-rect and compatible with transfer switch ratings, turn OFF the
UTILITY supply to the transfer switch.
6. Set the generator’s main circuit breaker (CB1) to its OFF or OPEN position.
7. Set the AUTO/OFF/MANUAL switch to the OFF position to shut down the generator.

GENERATOR TESTS UNDER LOAD
1. Set the generator's main circuit breaker to its OFF or OPEN position.
2. Manually actuate the transfer switch main con-tacts to their EMERGENCY (STANDBY) position. Refer to “Manual
Operation”.
3. To start the generator, set the AUTO/OFF/ MANUAL switch to MANUAL. When engine starts, let it stabilize for a few
minutes.
4. Turn the generator's main circuit breaker to the ON or CLOSED position. The generator now powers all LOAD
circuits. Check generator operation under load as follows:
a. Turn ON electrical loads to the full rated watt-age/amperage capacity of the generator. DO NOT OVERLOAD.
b. With maximum rated load applied, check voltage and frequency across transfer switch terminals E1 and E2.
Voltage should be greater than 200 volts (208VAC system), 230 volts (240VAC system), or 460 volts
(480VAC system); frequency should be greater than 59 Hz.
c. Let the generator run under rated load for at least 30 minutes. With unit running, listen for unusual noises,
vibration, overheating, etc., that might indicate a problem.
5. When checkout under load is complete, set main circuit breaker of the generator to the OFF or OPEN position.
6. Let the generator run at no-load for several minutes. Then, shut down by setting the AUTO/OFF/MANUAL switch to
its OFF position.
7. Move the switch's main contacts back to the UTILITY position. For example, load connected to utility power supply.
Refer to “Manual Operation”. Handle and operating lever of transfer switch should be in down position.
8. Turn on the utility power supply to transfer switch, using whatever means provided (such as a utility main line circuit
breaker). The utility power source now powers the loads.
9. Set the generator's AUTO/OFF/MANUAL switch to its AUTO position. The system is now set for fully automatic
operation.
PDU-ATS-100A-208Y.120-3PH
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Section 5 — Mounting Dimensions
RTS “W” Type Transfer Switch
Mounting Dimensions - 100/200A 208V
513.04mm[20.2"]
613mm[24.1"]
TRIPLE EKO SUITABLE FOR 1", 1.25" & 1.50" CONDUIT 3 PLACES
179.5mm[7.1"]
490mm[19.3"]
61.5mm[2.4"]
41.5mm[1.6"]
MOUNTING HOLES:
Ø6.35mm[Ø0.25"]
4-PLACES
430mm[16.9"]

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Section 5 — Mounting Dimensions
RTS “W” Type Transfer Switch
Mounting Dimensions - 100A 480V
609.6mm[24.0"]
917mm[36.1"]
TRIPLE EKO SUITABLE FOR 1", 1.25" & 1.50" CONDUIT 3 PLACES
254mm[10.0"]
794mm[31.3"]
60.8mm[2.4"]
61.3mm[2.4"]487mm[19.2"]
MOUNTING HOLES:
Ø6.35mm[Ø0.25"]
4-PLACES

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332mm[13.1"]
TRIPLE EKO SUITABLE FOR 1", 1.25" & 1.50" CONDUIT 3 PLACES
1220.9mm[48.1"] 1092mm[43.0"]
63.5mm[2.5"]
765.8mm[30.1"]
65.39mm[2.6"]
MOUNTING HOLES:
Ø6.35mm[Ø0.25"]
4-PLACES
635mm[25.0"]
Section 5 — Mounting Dimensions
RTS “W” Type Transfer Switch
Mounting Dimensions - 200A 480V

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Section 6 — Electrical Data
RTS “W” Type Transfer Switch
Interconnection Diagram
DIFFERENT CONDUITS. RUN IN TWO LEADSMUST BE TRANSFER SWITCH POWER LEADSAND NOTE:
SINGLE PHASE
UTILITY SUPPLY FROM
SERVICE DISCONNECT
23
USED ON 3PHASE SYSTEMS
NOTE: E3, N3AND T3WIRESARE ONLY
NOTE:
178AND 183
APPLICATION NOT USED IN THIS CONNECTIONSARE
194
ECONNECTION
WIRE 178
CUSTTOMER
8 7
NEUTRAL BLOCK
CONNECTION PANEL
QT SERIESENGINE GENERATOR
E1
N1
E2 (E3)
ON
3PHASE
E1 E2
(T3)T2T1
0F4034-
CUSTOMER LOAD
(DISTRIBUTION PANEL)
WIRE
WIRE
N1
N2
WIRE
WIRE
057329-T
NEUTRAL BLOCK
GROUND
RTSTRANSFER SWITCH
(E3)
E2
E1
T1
B
0D7295
T3T2
(N3)
N1
N2

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Section 6 — Electrical Data
RTS “W” Type Transfer Switch
Wiring Diagram/Schematic 100/200A, 208V
B2A2
B1A1
C
6
9
TR
1
7
TR
E1
E1
N2A
N2A
N1B
E2
205
126
TR
23
194
23
194
N2A
LEGEND
GTS
NOTES:
1.) ALL CONTACTSSHOWN WITH
TRANSFER SWITCH IN UTILITY
POSITION.
B
A
WHITE
RED
LS2
LS3
LS1
T1 T2
235 6
1 4
3
4
5
N1B
N2A
N3
PM
N1B N1A
PM
F2
N2
N1
F1
N1B
N2A
126
C - CONTACTOR ACTUATING COIL
GTS- TRANSFER SWITCH CONTACTOR
PM - POWER MONITOR, 3PHASE UTILITY
TR - RELAY, TRANSFER
TS- TERMINAL STRIP (CUSTOMER CONNECTION)
LS1,LS2,LS3 - LIMIT SWITCHES, ACTUATOR
F1,F2 - FUSE 5A SENSING
18
ADD JUMPER WIRE FROM PM
TERMINALS1 TO 8.
2.) FOR SINGLE PHASE OPERATION,

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Section 6 — Electrical Data
RTS “W” Type Transfer Switch
Wiring Diagram/Schematic 100/200A, 208V
TR
GTS
T1
E1
N1
T2
E2
N2
B1
B2
A2
A1
N1B
N1B
126
E2
E1
N2A
205
N1B
205
E1E1
A 7 1
B 9 36
T1
T2
N1B
N2A
N3
E3
T3
2 1 87
34 5 6
126
205
N2A
N2A
N2A
N1B
N1B
N1B
N1B
N1A
N3
PM
N3
N3
N1B
N1B
F2
F1
23
194
TS
UTILITY 2
UTILITY 1
N2A
N2A
N2A
N3
N3N3
194
23
23
194
23
194
N1
N2
N2A
N2A
N2A
N2A

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Section 6 — Electrical Data
RTS “W” Type Transfer Switch
Wiring Diagram/Schematic 100/200A, 480V
B2A2
B1A1
C
6
9
TR
1
7
TR
E1A
E1A
N1A
E2A
205
126
TR
23
194
LEGEND
ATS
NOTES:
1.) ALL CONTACTS SHOWN WITH
TRANSFER SWITCH IN UTILITY
POSITION.
B
A
RED
LS2
LS3
LS1
T1 T2
2 3 5 6
1 4
3
4
5
N2A
N3
PM
N1B
PM
F2
N2
N1
F1
N2B
126
1 8
TR1
240V
X4
X1
OR
600V
H4
480V
H1
H1
X4
240V
X1
H4
480V
OR
600V
TR2
N1C
N2B
N2B
N2B
23
194
E1
E2
ATS - TRANSFER SWITCH CONTACTOR
C - CONTACTOR ACTUATING COIL
PM - POWER MONITOR, 3 PHASE UTILITY
TR - RELAY, TRANSFER
TS - TERMINAL STRIP (CUSTOMER CONNECTION)
LS1,LS2,LS3 - LIMIT SWITCHES, ACTUATOR
F1,F2 - FUSE 5A SENSING
TR1,TR2 - TRANSFORMER STEP DOWN

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TR2
TR1
47822-T
TR
ATS
T1
E1
N1
T2
E2
N2
B1
B2 A2
A1
A 7 1
B 9 3
T1
T2
N3
E3
T3
2 1 8 7
3456
PM
F2
F1
H4
X4 X1
H1
H4
X4 X1
H1
UTILITY 1
UTILITY 2
1
TB 234
23
194
5
Z
Y
NB
N2B
205
E2A
126
N2B
N3
N2A
N1A
E1A
N1A
N2A
E2A
E2
E1
N3N3
194
E1A
23
205
N2
N1
23
194
E1 E2
N2AN1A
N1A
N2A
N1A
N2A
E2A
N3
N1C
N1C
N1C
N2B
N2B
N2B
N1B
N1B
N1B
N1B
N1B
Section 6 — Electrical Data
RTS “W” Type Transfer Switch
Wiring Diagram/Schematic 100/200A, 480V

THESE INSTRUCTIONS MAY NOT COVER ALL DETAILS OR VARIATIONS OF THIS PRODUCT FOR YOUR EQUIPMENT OR INSTALLATION REQUIREMENTS.
SHOULD FURTHER INFORMATION NOT COVERED BY THESE INSTRUCTIONS BE REQUIRED, PLEASE CONTACT LARSON ELECTRONICS BY EMAIL AT
[e-mail] OR BY PHONE AT 1-800-369-6671 FOR FURTHER ASSISTANCE.
PLEASE VISIT LARSONELECTRONICS.COM FOR WARRANTY AND RETURN INFORMATION.
USE AND CARE
Unauthorized modification may impair the function and/or safety of this device and could affect the life of the equipment.
Always check for damaged or worn out parts before using the device. Store it in a secure place out of the reach of
children when not in use.Inspect for good working condition prior to storage and before re-use.
REPLACEMENT PARTS
The PDU-ATS-100A-208Y.120-3PH is designed to provide years of reliable performance. Should the need for
replacement parts arise, please contact Larson Electronics.
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PDU-ATS-100A-208Y.120-3PH