The 4-Wire Transformer Cabinet transforms the 3-wire utility input and flywheel discharge output to a 4-wire service.
Cabinet Description
The 4-Wire Transformer Cabinet is an optional 42-inch wide cabinet that is located to the left of the Maintenance Bypass Cabinet, if the Maintenance Bypass Cabinet is present in the system. If the Maintenance Bypass Cabinet is not present, the 4-Wire Transformer Cabinet will be located to the left of the Input/Output Cabinet.
The 4-Wire Transformer Cabinet contains a large transformer that has a 4-wire Wye output.
There are two versions of the 4-wire cabinet hardware:
- Version 1
- Version 2
Locate and identify the proper hardware installation steps and images for the cabinet version on which you are working.
Hardware Version 1
The left panel of the 4-Wire Transformer Cabinet contains the T12 and T13 fan control power transformers.
The right panel contains the T14 and T15 control power transformers. The T14 transformer is used to power fan number three and the T15 transformer is used to power the 4-Wire Thermal Switch Monitor Board that is located on the fan plenum shield.
The three fans are located at the bottom of the cabinet and located above is the fan plenum shield.
The fan plenum shield contains three boards, the secondary current transformers, and the system fuses.
The following boards are on the fan plenum shield: General Purpose Interface Board, External Source Sync Board and 4-Wire Thermal Switch Monitor Board.
Hardware Version 2
The top section of the 4-Wire Transformer Cabinet contains the T12 to T16 control power transformers.
The T12, T13, T14, and T16 control power transformers are used to power the four fans at the bottom of the cabinet. The T15 transformer is used to Power the 4-Wire Thermal Switch Monitor Board that is located on the top panel.
The top panel contains three boards, the secondary current transformers, and the system fuses.
The three boards on the top panel are the General Purpose Interface Board, the External Source Sync Board and the 4-Wire Thermal Switch Monitor Board.
Both
The General Purpose Interface Board receives data from the fan speed sensors and the temperature thermistors on the 4-Wire Transformer.
The External Source Sync Board digitizes the transformer output voltage and currents and sends it to the APC2 controller for monitoring purposes. There is also an additional voltage feedback that is used for the external source sync option.
Note: In a UPS configuration with a 3-wire output, the External Source Sync Board option is located in the Input/Output Cabinet.
The Thermal Switch Monitor Board takes inputs thermal switches that are located on the 4-Wire Transformer and illuminates the Over Temperature Notice Indicator on the front door of the cabinet. The Thermal Switch Monitor Board also has customer contacts that are wired to a terminal strip that is located in the 4-Wire Output Cabinet for thermal fault monitoring.
The locations of the following components are in the upper part of the cabinet: 3-Wire Input Bus Bars, 4-Wire Output Bus Bars and Primary Current Transformers.
The primary voltage for the transformer, either from the UPS source or from the discharging flywheels, enters the cabinet from the right side bus bars and connects to the three inputs of the 4-Wire Transformer at the rear of the cabinet.
The secondary voltage of the transformer exits the 4-Wire Transformer from the three outputs at the front of the Transformer. There is one for each phase (A, B, and C).
The four outputs bus bars that are located in the front of the cabinet pass through the left side of the cabinet into the 4-Wire Output Cabinet.
Cabinet Diagrams
4-Wire Transformer Cabinet (Version 1)
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| Illustration 1 | g01271508 |
4-Wire Transformer Cabinet - Front Doors - Version 1 and 2 Hardware (1) Front Door Status Indicator (2) Air Filters (3) Ground | |
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| Illustration 2 | g01271510 |
4-Wire Transformer Cabinet - Left View - Version 1 (6) Left Panel (7) 4-Wire Transformer (8) Ground (9) Fans (10) Fan Plenum Panel | |
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| Illustration 3 | g01271512 |
4-Wire Transformer Cabinet - Right View - Version 1 (7) 4-Wire Transformer (9) Fans (10) Fan Plenum Panel (11) Right Panel | |
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| Illustration 4 | g01271514 |
4-Wire Transformer Cabinet Left Panel - Version 1 | |
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| Illustration 5 | g01271517 |
4-Wire Transformer Cabinet Right Panel - Version 1 | |
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| Illustration 6 | g01271519 |
4-Wire Transformer Cabinet Fan Plenum Panel - Version 1 (16) General Purpose Interface Board (17) External Source Sync Board (18) 4-Wire Thermal Switch Monitor Board (19) Fuses F96, F97 (20) Secondary Current Transformers (CTs) (21) Fuses F58-F60 (ESS) F61-F63 (22) Fuses F73-F76, F94, F95 | |
4-Wire Transformer Cabinet - (Version 2)
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| Illustration 7 | g01271508 |
4-Wire Transformer Cabinet - Front Doors - Version 1 and 2 Hardware (25) Front Door Status Indicator (26) Air Filters (27) Ground | |
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| Illustration 8 | g01271521 |
4-Wire Transformer Cabinet - No Doors - Version 2 (30) Top Panel (31) Front Shield (32) Ground (33) Fans | |
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| Illustration 9 | g01271522 |
4-Wire Transformer Cabinet - Right View - Version 2 (33) Fans (34) Transformers T12-T16 (35) 4-Wire Transformer (behind shield) | |
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| Illustration 10 | g01271523 |
4-Wire Transformer Cabinet Upper Panel - Version 2 Hardware (16) General Purpose Interface Board (17) External Source Sync Board (18) 4-Wire Thermal Switch Monitor Board (19) Fuses F96, F97 (20) Secondary Current Transformers (CTs) (41) Fuses F61-F63 F103 (42) Fuses F73-F76, F94, F95, F104,105 (43) Fuses F64-F66 | |