UPS 120, UPS 150, UPS 250, UPS 300, UPS 301, UPS 500, UPS 600, UPS 750 and UPS 900 Uninterruptible Power Supplies Caterpillar

SMS Bypass Cabinet

Illustration 1	g03428384
Bypass Cabinets (Front View with Shields) (1) Bypass switch (optional) (2) Output switch (optional) (3) Input switch (optional) (4) Upper shield (5) Lower shield (6) GSM circuit breaker (optional)

Illustration 2	g01280608
(7) LCD display (8) Key switch (9) Home soft key

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When servicing or repairing electric power generation equipment: Make sure the unit is either locked out or tagged DO NOT OPERATE. Remove all fuses. Make sure the generator engine is stopped. Make sure all batteries are disconnected. Make sure all capacitors are discharged. Make sure residual voltage in the rotor, stator and the generator is discharged. Failure to do so could result in personal injury or death.

System Internal Bypass Procedure

The internal bypass is used when the system voltage must regulate the power to the load, but not protecting the load in a utility outage.

1. Turn the key switch (8) to the Bypass position at the flywheel cabinet.

2. Ensure that the UPS is in Bypass mode. Confirm the mode by pressing the "Home" soft key (9) . The "Home" is located on the user interface panel. Observe the status line on the LCD (7) .

The system is now in Internal Bypass.

SMS with Bypass Cabinet

Maintenance Bypass Procedure

Perform the maintenance bypass procedure. The voltage is not regulated and the load is not protected.

1. Turn the key switch (8) to Bypass position at the flywheel cabinet.

2. Ensure that the UPS is in Bypass mode. Confirm the mode by pressing the "Home" soft key (9) . The "Home" is located on the user interface panel. Observe the status line on the LCD (7) .

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NOTICE
If the system does not enter the Bypass mode, Do Not Proceed with this procedure. Equipment damage or load interruption may occur. Contact Technical Support.

Note: When the flywheel is spinning, the following components are energized: the DC bus, the armature leads and the fuses (armature). In order to brake the flywheel, follow the procedure inSystems Operation, Testing and Adjusting, RENR9988, "System Pre-Shutdown ".

3. Close the bypass switch (1) that is located in the bypass cabinet.

4. Open the output switch (2) that is located in the bypass cabinet.

5. Open the input switch (3) that is located in the bypass cabinet.

The system is now in Maintenance Bypass.

Follow procedures in Systems Operation, Testing and Adjusting, RENR9988, "System Startup (SMS)" to return from maintenance bypass.

SMS without Bypass Cabinet

Maintenance bypass procedure

This procedure is used when there is not a bypass cabinet in order to control the maintenance bypass. Possibly an external wrap-around bypass system is carried out.

1. Turn the key witch (8) to Bypass position at the flywheel cabinet.

2. Ensure that the UPS is in Bypass mode. Confirm the mode by pressing the "Home" soft key (9) . The "Home" is located on the user interface panel. Observe the status line on the LCD (7) .

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NOTICE
If the system does not enter the bypass mode, Do Not Proceed with this procedure. Equipment damage or load interruption may occur. Contact technical support.

Note: When the flywheel is spinning, the following components are energized: the DC bus, the armature leads and the fuses (armature). In order to brake the flywheel, follow the procedure inSystems Operation, Testing and Adjusting, RENR9988, "System Pre-Shutdown ".

3. Close the external bypass switch.

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NOTICE
Make sure that the circuit path to the customer load is unaffected when performing the following steps, so that the load is not dropped.

4. Remove electrical input to the UPS.

5. Disconnect the electrical path from the output of the UPS for electrical feedback prevention to the UPS.

   The system is now in maintenance bypass.

Follow procedures in Systems Operation, Testing and Adjusting, RENR9988, "System Startup (SMS)" to return from maintenance bypass.