Emerson 7000 SERIES ATB manual Install the Transfer Switch

INSTALLATION (continued)

Install the Transfer Switch

After the enclosure is installed and power cables or bus connected to the Bypass Switch, the Transfer Switch carriage can be rolled in. The floor of the cabinet must be free of debris and clean. If necessary, use a vacuum cleaner. Make a thorough inspection to be sure no tools are left inside. The Bypass Handle must be in the BYPASS POS position (closed on normal). The Isolation Handle (draw- out crank) must be fully counterclockwise against stop.

Do not apply any electrical power to the ATB yet.

It is not necessary to remove the barriers from the bypass switch and transfer switch. If you do remove them, however, reinstall them carefully.

NOTE: Be sure to roll the correct Transfer Switch into the enclosure. If more than one is supplied, each will be labeled above the solenoid operator.

The Transfer Switch NORMAL contacts must be closed. If not, use the manual operator handle (maintenance handle stored on lower carriage) to manually operate the switch. See Figure 1–10. Check that all arc chutes and interphase barriers are in place on the Transfer Switch. Then grasp the Transfer Switch carriage frame and roll it into the cabinet (isolation contacts facing inward). Align the rollers between the floor guides and push the carriage in until its crank pins engage the latch plates on both sides. Then follow the procedure below:

NOTE: Solenoid lock SL1 on the Isolation shaft inhibits operation of the drawout (Isola- tion contacts) unless the Transfer Switch and Bypass Switch are in compatible positions. This solenoid must energize to unlock. Be- cause all power sources are de-energized, the interference tag defeats the solenoid in the following inspections.

Do the three inspections on page 1-4 without any electrical power connected. The inspections will verify that the isolation contacts are in proper alignment. If necessary, add shims under the floor. It may be helpful to remove the the right side of the enclosure to expose the isolation contacts during the inspections.

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Do not apply any power to the Bypass Switch. Be sure that the Normal and Emergency source circuit breakers are OPEN before proceeding.

Remove interference tag after making inspection

on page 1-4. SL1 solenoid

lock

handle

carriage	Isolation
frame	Handle shaft

Figure1–2. Solenoid latch interference tag.

Turn the draw-out crank while checking alignment of the isolation contacts.

Figure 1–3. Isolation Handle.

Transfer Switch

NOMINAL CONTACT GAP 1/8” WHEN OPEN.

Figure 1–4. Switched neutral interlock.

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