Eaton SPB Drawdown Switch Maintenance Guide

Detailed explanation of Drawout Mechanism

The pull-out mechanism allows switch components to be removed or inserted without dismantling the primary cable. It has four positions:

Description of secondary control contacts for position main circuit contacts

CONNECTED is connected to its normal working position

TEST disconnection and connection can test the control circuit, but the load is not powered

DISCONNECT: Disconnected and isolated state

WITHDRAWN: The disconnect switch can be fully withdrawn

4.1 Shake in and shake out operation

Use a 3/4 inch socket wrench to insert the pull-out drive shaft (Figure 6-1), rotate clockwise to move the switch in the CONNECTED direction, and counterclockwise to move it in the WITHDRAWN direction. Before operation, the padlock wrench must be lifted. If the contact is forcefully shaken when closed, the switch will automatically trip (causing the load to lose power).

4.2 Operation interlock

The switch can only be closed in the CONNECTED, TEST, DISCONNECT positions. Unable to close at WITHDRAWN position.

The mechanical interlock of the bracket ensures that the switch is always in the open state when connecting or disconnecting the main contact.

4.3 Switch extraction and rotation maintenance

When it is necessary to rotate the switch component for inspection, first return the switch to the DISCONNECT position and remove the dead front shield on the front panel. Then pull out the switch to make the front wheel leave the guide rail and continue to straighten it forward until the rear wheel enters the original groove of the front wheel (Figure 6-2, 6-3). When rotating, pay attention to protecting the secondary control plug, reset it after completion, and reinstall the dead baffle.

Operation Guide for Bypass Isolation Switch

The bypass isolation type (BI) transfer switch allows for maintenance or replacement of the main switch without interrupting the load power supply. It includes four sets of switches: normal switch, emergency switch, normal bypass switch, and emergency bypass switch.

5.1 Indicator Light Panel Description

Meaning of panel indicator lights:

Normal Isolated: The normal switch has been pulled out and the main circuit is disconnected

Emergency Isolated: The emergency switch has been pulled out

Normal Bypass: The normal bypass switch has been closed

Emergency Bypass: The emergency bypass switch has been closed

Normal Position Energized: The normal switch supplies power to the load

Emergency Position Energized: The emergency switch supplies power to the load

5.2 Typical operation: Switch the normal switch to the bypass and isolate it

Set the generator set selector switch to OFF to prevent accidental start-up.

Remove the key from the emergency switch key interlock (rotate counterclockwise while pushing the lever upwards), the emergency switch is locked and cannot be closed.

Insert the key into the normal bypass switch and turn it clockwise to unlock.

Manually close the normal bypass switch → the "Normal Bypass" light is on.

Open the switch and shake out the normal switch (see Section 4) → The "Normal Isolated" light is on, and the "Normal Position Energized" light is off.

Check and repair the normal switch.

Shake in the normal switch → the switch automatically stores energy and closes → the "Normal Isolated" light goes off, and the "Normal Position Energized" light comes on.

Open the normal bypass switch and turn off the "Normal Bypass" light.

Remove the key from the bypass switch (rotate counterclockwise) to lock the bypass switch.

Insert the key back into the emergency switch and unlock clockwise.

Restore normal automatic operation.

The operations of emergency side bypass, normal → emergency bypass, emergency → normal bypass, etc. are detailed in section 7.3 of the manual, and the principles are similar.

5.3 Manual switching in bypass mode

Switching from normal bypass to emergency bypass: First lock the normal switch (take the key), unlock the emergency bypass switch, open the normal bypass, and close the emergency bypass.

The reverse operation is the same.

Testing and troubleshooting

6.1 Regular testing

Mechanical and electrical testing should be conducted after installation and during planned power outages. Mechanical testing involves manual energy storage and opening/closing of switches; The electrical test uses the test button on the panel (if any), and must be turned back to the "AUTO" position after the test.

6.2 Common Fault Handling Process

Problem 1: The conversion switch does not work at all

Step 1: Check if all plugs and sockets are securely plugged in.

Step 2: Measure whether the voltage at the normal switch terminal reaches the system voltage.

Step 3: Check if the voltage selection plug is in the correct position.

Step 4: Observe for any obvious burnt components, identify the cause, and replace them.

Step 5 (Closed Conversion Type): Refer to Figure 5-2 for manual operation and check if there is power on the load side. If not, check the power connection and switch mechanism.

Step 5 (Switching type): Press the close button of the normal switch to check if there is power on the load side.