Eaton SPB Drawdown Switch Maintenance Guide

Problem 2: Cannot automatically switch to the normal side

Check if the voltage of N1, N2, and N3 lines is normal.

Has the normal switch stored energy? If energy storage is not available, first address the issue of "switch not automatically storing energy".

Has the emergency switch been turned off? If not disconnected, handle it first.

Measure whether there is 120VAC ± 10V between terminals A9-A8 of the shunt release coil of the emergency switch. If there is, check the shunt coil; If there is none, check the wiring.

Measure whether there is 120VAC ± 10V between terminals A1-A2 of the closing coil of a normal switch. If there is, check the closing coil; If there is none, check the wiring.

Problem 3: Cannot automatically switch to the emergency side

Check the voltage of E1, E2, and E3 lines.

Does the emergency switch store energy? If not, handle it first.

Measure the voltage of the shunt coil A9-A8 of the normal switch (which should be 120V).

Measure the voltage of emergency switch closing coils A1-A2.

Problem 4: The switch does not automatically store energy

Measure the voltage between terminals A6 and A2 of the non energy storage switch, which should be 120VAC ± 10V. If there is voltage, check the internal electric operator of the switch; If there is no voltage, check the A6-A2 wiring.

If the above steps are still not resolved, record the SO number, GO number, catalog number, and other information, and contact Cutler Hammer technical support.

Maintenance and spare parts replacement

7.1 Regular maintenance cycle

Suggest following Table 9.1:

Monthly: visually inspect for dust, foreign objects, looseness, and signs of overheating.

Every six months to one year: power off, clean dust (use a vacuum cleaner, prohibit high-pressure blowing); Check and tighten the terminals; Check the insulation for cracking and carbonization once; Check the secondary control wiring.

For NEMA 3R type: Check the air filter and replace it if clogged (order number TSAFDO).

7.2 Handling when the switch is not frequently activated

If the switch is not switched during operation for a long time, it should be manually stored and opened/closed regularly to allow the contacts to produce wiping action and prevent oxidation.

7.3 Removal of NEMA 1 and NEMA 3R enclosure cover plates

NEMA 1: Use a 3/8-inch wrench to remove the screws (and finally remove the top screw), place your foot on the bottom to slowly tilt the top, and then lift up the cover plate. When reinstalling, first hang it into the bottom, push it into the top, and tighten the screws (torque 8 ft lbs).

NEMA 3R: Keep the sealing gasket when disassembling, use the randomly provided cover plate to lift the handle and insert it into the screw hole, pull out the cover plate to detach the lower flange from the lower crossbeam. When installing, first slide the flange on the cover plate under the roof flange, then push it into the lower part, install screws and sealing washers, and apply the same torque of 8 ft lbs.

7.4 Common spare parts

Air filter replacement kit: TSAFDO (Figure 10-1)

Replacement kit for padlockable handle: TSDPZFS (Figure 10-2)

Safety precautions and compliance with standards

Dangerous voltage: After opening the cabinet door, there is a lethal voltage inside. Before maintenance, the upstream power supply must be disconnected and locked.

Closed conversion model: The contact overlap structure is special, and any misoperation (such as forced opening and closing during parallel connection) may cause serious accidents. Be sure to follow Figure 5-3.

Pull out operation: If the contact is closed when lifting the padlock wrench, the switch will automatically trip, causing the load to lose power. Make sure to disconnect before pulling out the rack.

UL standard: SPB transfer switch complies with UL1008 (automatic transfer switch), UL489 (circuit breaker), and UL1087 (insulated shell switch), and has passed cUL certification. NFPA 99/110 is optional.

Seismic resistance: Option 42 provides UBC Zone 4 seismic resistance certificate, but must be installed strictly using clamps according to Figure 4-1.