Eaton Electrical RTC-50 instruction manual Glossary, Functions/Features

Instructional Booklet

Instruction Manual for the Eaton RTC-50 Automatic Transfer Switch Controller

Effective: June 2007 Page 3

A standard RTC-50 controller will:

•Monitor Utility and Generator power source voltages

•Provide undervoltage protection of the Utility and Generator power sources

•Permit easy customer set-up

•Provide source status indications

•Provide remote indication that generator maintenance needs to be performed

1.4 Glossary

With respect to their use within this document and as they relate to transfer switch and controller operation, the following terminol- ogy is defined.

Available

A source is defined as “available” when it is within its undervolt- age setpoint range.

Connected

Connected is defined as when the input is shorted by an external contact or connection.

Failed or Fails

A source is defined as “failed” when it is outside of the applicable voltage ranges for the nominal voltage and for a time exceeding

0.5seconds after the time delay emergency fail (TDEF) time delays expires.

Failsafe

Failsafe is a feature that prevents disconnection from the only available power source and also forces a transfer or re-transfer operation to the only available power source.

Re-Transfer

Re-transfer is defined as a change of the load connection from the Generator to the Utility.

Utility

Utility is the primary source (normal source, normal power source, or normal).

Generator

Generator is the secondary source (emergency source, emergency power source, emergency, standby, or backup source).

Utility: Failed or Fails

Utility is defined as “failed” when it is outside of its undervoltage setpoint range.

Generator: Failed or Fails

Generator is defined as “failed” when it is outside of its undervolt- age setpoint range for a time exceeding 0.5 seconds after the TDEF time delay expires.

Transfer

Transfer is defined as a change of the load connection from the Utility to the Generator power source.

Unconnected

Unconnected is defined as when the input is not shorted by an external contact or connection.

1.5 Functions/Features

The primary function of RTC-50 controller is to accurately monitor the Utility and Generator power sources and provide the necessary intelligence to operate the ATS in an appropriate and timely man- ner. In addition, the RTC-50 controller provides status information through on-board and remote indicators.

The following is a list of the features of the RTC-50 controller.

1.Time Delay Normal to Emergency (TDNE)

This feature provides a time delay when transferring from the Utility to the Generator power source. Timing begins when the Generator becomes available. It permits controlled trans- fer of the load circuit to the Generator.

Jumper selectable at 20 or 50 seconds. Default is 20 sec- onds.

3.Time Delay Emergency to Normal (TDEN)

This feature provides a time delay of the re-transfer operation to permit stabilization of the Utility source. Timing begins when the Utility becomes available. If the Generator fails during timing, then re-transfer is delayed for up to 6 seconds to allow the Generator to recover.

Fixed setting of 10 seconds

5.Generator Monitoring and Protection

This feature provides monitoring and protection based on the Generator voltage setpoints. All feature 5 functions are fail- safe operations.

5J. All Phase Undervoltage Protection

Dropout: 168 Vac (70% of 240 Vac nominal)

Pickup: 192 Vac (80% of 240 Vac nominal)

7.Time Delay Emergency Fail (TDEF)

This feature provides a time delay that prevents a connected Generator source from being declared “failed” in order to override momentary generator fluctuations. If the Generator remains in the failed state then, after the TDEF timer expires, the transfer switch will proceed with the programmed sequence for re-transfer.

Fixed setting of 6 Seconds

12.Power Source Annunciation

This feature provides LEDs to indicate power source availabil- ity.

12G. Utility - Available

This feature provides a green LED that, when lit, indicates that the Utility is available.

12H. Generator - Available

This feature provides a red LED that, when lit, indicates that the Generator is available.

15M. Load Shed

Two sets of contacts are available and can be used to control large connected loads on the Generator (i.e. air conditioners, hot tubs, etc.). The contacts are rated for 250 Vac, 5 amps.

IB00405004E-70-8664 For more information visit: www.eaton.com