ABB Zenith ZTSCT Series User Manual

ABB Zenith
21
ZTSCT / ZBTSCT Operation & Maintenance Manual
Testing
(cont’d)
Closed Transition
ABB Zenith Closed Transition Transfer Switches are designed
to Transfer the Load between two available sources without
interrupting power to the Load (Make-Before-Break).
Paralleling of the two sources occurs within a predefined
window of synchronization and lasts less than 100 millisec-
onds. The initial Source is then disconnected.
Initiating a Closed Transition
When a Test is initiated, the controller initiates the Time
Delay Source 2 Start (Engine Start Timer “P”) cycle. Upon
completion of the (P) time delay, an Engine start Signal
is sent to Source 2. When Source 2 voltage and frequency
reach the preset “Restore” values, the time delay to open
Source 1 timer (W) begins its timing cycle. After the (W)
time delay, the ATS closes into Source 2 only after the
controller ensures the proper phase relationship between
the two Sources. After the ATS closes into Source 2, the
SE limit switch becomes activated. The controller initiates
a transfer signal through the SCR-NO which opens the ATS
out of Source 1. The SNO limit switch activates. The ATS
has now closed into Source 2 position without interrupting
the load.
Retransfer with Closeed Transition
Deactivating the Test Switch initiates
the re-transfer. When
Source 1 voltage and frequency reach the preset “Restore”
values, the time delay to open Source 2 timer (T) begins
its timing cycle. After the (T) time delay, the ATS closes
into Source 1 only after the controller ensures the proper
phase relationship between the two Sources. After the
ATS closes into Source1, the SN limit switch becomes
activated. The controller initiates a transfer signal through
the SCR-EO which opens ATS out of Source 2. The SEO
limit switch activates. The ATS has now closed back into
Source 1 position without interrupting the load.
The ATS defaults to an open transition transfer when
Source 1 fails. Closed transition transfer is not possible
with only one source available. If the optional Transition
Mode Selector (TMS) is available, one can select an Open
Transition Transfer or a Closed Transition Transfer when
both Sources are available.
If while in Closed Transition Mode, the ATS fails to open
the source it is attempting to “transfer out of ” within
100 milliseconds, an Alarm will sound and the source
that the ATS just closed into will be opened leaving the
ATS in its initial source while disabling all other transfer
operations until the problem is corrected and the “Fail
to Open Lockout Reset” has been pressed.
A signal will be provided (STE) to Shunt Trip the Generator
Circuit Breaker if the Transfer Switch remains closed into
both Sources for more than 325 milliseconds. The load
will then be fed by the Source 1. The maximum time that
the two Sources would be parallel, under these conditions,
is less than 500 milliseconds. Before operating the Closed
Transition Transfer Switch, the condition must be corrected
and the Shunt Trip reset. Refer to procedure for servicing
the Switch after Shunt Tripping occures.
The unit is Factory set to accomplish transfer within
5 electrical degrees.
Requires an Isochronous Governor with an operating
frequency of 60+/- 0.2 Hz.
Requires a Shunt Trip Breaker on the Generator set
with a response time not exceeding 50 milliseconds.
A periodic test of the transfer switch under load conditions is recommended to insure proper operation.
(See National Electric Code articles 700 and 701)
NOTICE

ABB Zenith ZTSCT Series Specifications

General

Poles	2, 3, 4
Series	ZTSCT Series
Manufacturer	ABB
Amperage Range	30A to 4000A
Voltage	Up to 600 VAC
Operation	Automatic
Standards	UL 1008, CSA C22.2 No. 178
Enclosure	NEMA 1, 3R, 4, 12
Transfer Type	Open or Closed Transition

Summary

Introduction

Safety

Installation

Power Connections

Specifies wire sizes, number of cables, and torque values for terminals.

Engine Start Control Connections

Explains connections for engine start control wires to the microcontroller.

Initial Energization

Step-by-step procedure for initial power-up and verification of the transfer switch system.

Control Connections

Details the wiring and connections for the control panel and microprocessor.

Entelli-Switch 250 Controller

The Microprocessor

Details the components of the microprocessor, including the I/O interface and accessories.

User Setting for Voltage & Frequency

Source 1

Details the adjustable parameters for Source 1, including Under/Over Voltage and Frequency settings.

Source 2

Details the adjustable parameters for Source 2, including Under/Over Voltage and Frequency settings.

Accessory Group Packages

Accessory Definitions

How to Set the System Clock

Set System Clock, time and date

Instructions for setting the system clock, time, and date for the controller's accurate operation.

CDT One Event Timer Exerciser

CDP Clock Exerciser

Entelli-Switch 250 User Setup - CFG Menu

Entelli-Switch 250 User Setup - SET Menu

Entelli-Switch 250 User Setup - System Info

Testing

Test Options

Describes the two test positions: "Auto Position" for full transfer and "Test Position" for PM without load interruption.

ATS Testing

Detailed steps for initiating and performing ATS tests, including load and no-load options.

Open Transition

Explains the sequence of operation during an open transition transfer due to source failure or restoration.

Closed Transition

Details the operation of closed transition transfer switches, including paralleling and synchronization.

Initiating a Closed Transition

Steps to initiate a closed transition test, including engine start and synchronization procedures.

Retransfer with Closed Transition

Describes the process of retransferring to the original source with closed transition, ensuring phase relationship.

Emergency Service Procedure for Extended Parallel Time

ZTSCT Transfer Switch

Steps to safely open the ZTSCT transfer switch after an extended parallel time malfunction.

ZBTSCT Transfer/Bypass Switch

Procedures for removing ZBTSCT switches after shunt trip or for inspection and repair.

Sequence of Operation

Bypass-Isolation Operation

Explains how the bypass-isolation switch allows ATS withdrawal for testing/maintenance without load interruption.

100-400 AMP

Details the automatic, bypass, test, isolate, and reconnect sequences for 100-400 AMP models.

600-1200 AMP

Details the automatic, bypass, test, isolate, and reconnect sequences for 600-1200 AMP models.

1600-4000 AMP

Details the automatic, bypass, test, isolate, and reconnect sequences for 1600-4000 AMP models.

1600-3000 AMP Horizontal Bypass

Details the automatic, bypass, test, isolate, and reconnect sequences for 1600-3000 AMP Horizontal Bypass models.

Controls Power Supply (CPS)

Closed Transition CPS Schematic

Provides the schematic diagram for the Closed Transition Controls Power Supply.

Troubleshooting and Diagnostics

General Troubleshooting

Provides a systematic approach to diagnosing and determining basic faults in the transfer switch.

Maintenance and Testing

Inspection and Cleaning

Instructions for inspecting and cleaning the switch, including contact inspection and barrier checks.

Servicing

Guidelines for replacing worn parts and maintaining the transfer switch's operating mechanism.

Testing

Procedures for manual and electrical testing of the transfer switch operation.

Extensive Customer Service and Support

Product Overview

Describes ABB's commitment to quality and the benefits of their power management systems.

Commitment to the Customer

Outlines ABB's dedication to customer satisfaction and partnership throughout the system lifecycle.