ASCO Series 300 Automatic Transfer Switch Wiring Diagrams

Control Features

A. Differential Voltage and Frequency Settings: Adjustable via potentiometers on the control panel. Refer to the operator's manual for specific adjustment procedures.

B. Phase Sequence Check of Emergency Source: Ensures the emergency source is connected in the correct phase sequence. If incorrect, the transfer switch will not transfer.

C. Phase Sensing of Emergency Source: Monitors voltage and frequency of the emergency source. Transfer occurs only when the source is within acceptable ranges.

D. Non-Linear Source Delay - Activated When: Delay activated when the emergency source voltage is present but unstable. Transfer occurs only after the source has stabilized for the delay duration.

E. Transfer Switch Test Push-Button: Initiates a test transfer to the emergency source, followed by an immediate return to normal (if available). Can be performed manually.

F. Emergency Source Available Indicator: Light indicates the emergency source is available and within acceptable parameters; it does not confirm transfer.

Field Connections

Diagram shows field connections for the transfer switch, including remote control features and source availability signals. It details connections for the Control Panel (CP) and Transfer Switch (TS) components. Key connections include Engine Starting, Load Disconnect, Emergency Transfer Delay, and Normal Transfer Delay. Optional ACC. 11BG Source Availability Signals are also depicted, indicating 'Normal Not Available' or 'Emergency Available' states.

General Notes

Note 1: All wiring and components are in accordance with NEC, UL, CSA, and applicable standards.

Note 2: Diagrams are for ASCO Series 300 Automatic Transfer Switches with Group 1 Controls.

Note 3: Components and connections shown are representative. Refer to specific model documentation for exact configurations.

Note 4: Control points are wired for automatic operation. Connections for manual operation and remote control features are also shown.

Note 5: The transfer switch test push-button initiates a test transfer to the emergency source and then returns to normal (if available). This test can be performed manually at any time.

Note 6: Emergency source available indicator light shows when the emergency source is within acceptable voltage and frequency parameters.

Optional Accessories

ACC. 11BG: Programmable Engine Exerciser & Source Availability Signal. This accessory provides engine exercise functions and signals the availability of the emergency source.

ACC. 14AA & 14BA: These accessories likely relate to communication or advanced control functions, detailed in separate documentation.

ACC. 44A & 44G: These accessories are related to load connection or customer power supply options.

Catalog Number Chart

Main Power Poles

This diagram illustrates the main power distribution for the transfer switch, differentiating between EMERGENCY, LOAD, and NORMAL power circuits. It shows how the transfer switch (TS) connects to these circuits via components labeled EL (Emergency Line) and NL (Normal Line) contacts. The diagram also indicates that the ATS is shown in its closed state on the NORMAL source.

TS Operator Circuit

This schematic details the internal operator circuit of the Transfer Switch (TS). It includes control contacts, solenoid position indicators, and connections to the Control Panel (CP). The diagram shows the TS solenoid coil and its associated control contacts, which manage the transfer operations based on signals from the control panel.

TS Control Contacts

Wire Run Listing

P-TS Harness

J-CP Harness

Optional Accessories Wiring

Control Signals & Indication

This section illustrates the control signals and indication pathways, including connections to the Control Panel (CP) and optional accessories. It shows how the programmable engine exerciser (ACC. 11BG) and other optional accessories interface with the transfer switch's control system. The diagram also depicts simplified representations of the Emergency Source Circuits, Load Terminal Circuits, and Normal Source Circuits, showing their connections to the ATS.

Source Circuits

Emergency Source Circuits: Depicts the electrical path for the emergency power source, connecting to the transfer switch via EL components.

Load Terminal Circuits: Shows the connections for the load that will be powered by the transfer switch, labeled as LOAD.

Normal Source Circuits: Illustrates the electrical path for the normal power source, connecting to the transfer switch via NL components.

Physical Diagram

This diagram provides a physical overview of the transfer switch enclosure. It shows the Transfer Switch (TS) viewed from the inside front, illustrating the arrangement of LL (Load Line) and NL (Normal Line) connections. The enclosure also houses the Group 1 Control Panel (CP) with its membrane panel, which includes operator interface and controls. Connections for optional accessories such as the ACC. 11BG (Engine Exerciser & Source Availability Signals) and the ASCO Optional Serial Communication Device are also indicated. A heater accessory and a bonding strap are also shown.

Operator Controls

This table lists the operator controls and indicators found on the transfer switch interface.