Eaton Power Circuit Breaker MDS-808

Warning: Breaker accessory voltages can vary within the same breaker. Be sure to review the accessory voltage rating before energizing as damage may occur.

This test procedure assumes that the breaker is equipped with optional shunt trip (ST), undervoltage release (UVR), and/or spring release (SR) accessories (Figure 94). If one accessory is missing, substitute the manual button or manual charge handle to replace the accessory’s function. If equipped with a motor operator, the voltage is listed on the breaker nameplate.

Enter the voltage of the motor operator

Did the breaker mechanism springs charge using the motor operator?

Did the breaker close by applying rated voltage to the spring release accessory?

Did the breaker mechanism springs charge using the motor operator again?

Did the breaker open by applying rated voltage to the shunt trip accessory?

Note: If UVR is not installed, proceed to step 7.

With UVR energized, did the breaker close using the spring release accessory?

Charge the breaker mechanism springs either using the charging handle or the motor operator

Press the ON pushbutton to close the breaker manually and verify closing by noting the state of the indicating flag

Charge the breaker mechanism springs either using the charging handle or the motor operator. If using the motor operator, disconnect power to it to prevent automatic recharging

Press the OFF pushbutton to manually open the breaker

Press the ON pushbutton to manually close the breaker. Is the breaker closed?

Press the OFF pushbutton to manually open the breaker. Is the breaker open?

Note: Repeat this entire described test procedure three times

Sign off on the manual operation functional testing

Pre-inspection conditions: Device(Fixed): Position of Poles: Open, Mechanism: Discharged, Device Position in Cassette: -. Device(Drawout): Position of Poles: Open, Mechanism: Discharged, Device Position in Cassette: Removed.

Circuit breaker's arc chutes and arc chambers free from damage or dirt

Signs of significant erosion of the V-shaped plated inside the arc chute

Arc chutes fit inside the arc chambers and down over the primary contacts. Each arc chute is held in place by either 1 (SB) or 4 (SBSE) top inserted screws.

Remove arc chute screws and all arc chutes from the arc chamber

Turn each arc chute upside down and visually inspect the inside

Look for erosion and sooty discoloration on the splitter plates and insulating jacket

If arc chutes show severe signs of erosion or discoloration, replace with a new arc chute

Note: Because the arc chutes are removed, this is an ideal time to inspect the primary contacts for wear (See Primary Contact Inspection procedure on page 59).

Warning: This procedure requires trained personnel with PPE!

Charged the breaker mechanism springs using the charging handle or the motor operator

Closed the breaker by applying rated voltage to the spring release accessory

Verified closing by noting the state of the indicating flag

Charged the breaker mechanism springs again using the charging handle or the motor operator

Disconnected power to the motor operator to prevent automatic recharging

Checked the state of the pop-out trip indicator

Reset the pop-out trip indicator if it was 'out'

Pressed the ON pushbutton to manually close the breaker

Device (Fixed): Position of Poles

Device (Fixed): Device Position in Cassette

Device (Drawout): Position of Poles

Device (Drawout): Device Position in Cassette

Inspect the breaker for nicked wires, cracks in plastic parts, and loose screws