CAP/PLUG-TAPERED 7E8716 - Caterpillar

The information in this section lists the main system earthing (grounding) arrangements (SEAs) and the wiring requirements.The normal and bypass AC lines are electronically (galvanically) isolated.Single UPS with TNS Upstream and TNS Downstream Configurations
Refer to the, "Glossary" section of this publication for a definition of TNS.Without Residual Current Protection
Illustration 1 applies to circuitry that does not have residual current protection.
Illustration 1 g02444560
Applies to input configurations that use separate normal and bypass AC lines from a single source.Note: Contact the dealership technical communicator for assistance with UPS units that are used as frequency converters.With Residual Current Protection
Electrical (galvanic) isolation between the normal and bypass AC lines is mandatory.The recommended minimum residual current protection is 3A, provided the conditions that are defined in IEC364.4-41 of the electrical code are respected.
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Transformer on a bypass AC network
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Transformer on a Normal AC networkNote: Adding a transformer into the "Normal AC" network reduces the overall efficiency of the installation.Single UPS with TNC Upstream and TNS, TNC, or TT Downstream Configurations
The UPS internal PE bar must be configured as a PEN bar. Refer to the "Neutral Point Connections" section of this publication for steps to configure the PE bar.For installations with an SSC or an external bypass cabinet, the internal PE bar must be configured as a PEN bar. Refer to the "Neutral Point Connections" section of this publication for steps to configure the PE bar.Single or Modular UPS Units
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For configurations that use separate normal and bypass AC lines from a single source (1) Internal PEN barThe UPS output neutral must be connected to the internal PEN bar (1). Refer to Illustration 4.Parallel UPS Units with an SSC or Modular UPS Units with External Bypass CabinetThe SSC output neutral or external bypass cabinet output neutral must be connected to the internal PEN bar for the cabinet in Illustration 4. The connection between the UPS outputs and the SSC or the external bypass cabinet must be done in TNC. That is, the PEN cable must be connected to the PEN bar. Note: The load neutral terminal on the UPS, SSC, or external bypass cabinet must not be used.Any electrical components or equipment that is connected to the UPS installation output is considered downstream to the UPS installed equipment. That is, any SEAs, TNS, or TT is considered to be downstream of the UPSB505 installation output.Single UPS with IT Upstream and IT Downstream Configurations
Illustration 5 g02446319
For configurations that use separate normal and bypass AC lines from a single sourceNormal Operating ModeThe IMD1 controls the entire installation that includes UPS-related equipment that is downstream from the UPS. Power for the IMD2 is switched off by the R2 relay. The R2 relay provides upstream voltage control to the UPS.The following events will occur if the voltage is removed or if the upstream voltage protection is opened:
The R1 relay will open the IMD1 circuit to disable upstream voltage to the UPS.
The R2 relay will close the IMD2 circuit to provide upstream voltage to the UPS. The voltage will provide