Siemens 480V manual RL Breaker Accessories / Modifications cont’d

480V Metal-Enclosed Switchgear

LV Power Circuit Breakers

General

4

480V Enclosed-MetalSwitchgear

RL Breaker Accessories / Modifications (cont’d)

Operation Counter

A mechanically-operated, 5-digit non- resetable counter can be mounted beneath the breaker auxiliary switch. The counter is incremented by the action of the auxiliary switch operating mechanism.

Undervoltage Trip Device

The undervoltage trip device protects against a drop in normal bus voltage and functions to directly trip the breaker. Pickup occurs at 85 percent or less of rated value and dropout between 30 and 60 percent of rated value. Pickup and dropout are individually adjustable. Instantaneous or time-delayed operation can be provided. The static timing unit is adjustable from 0.04 to 4 seconds for time delay. This allows the system to distinguish between undervoltage conditions and momentary voltage dips.

Table 4.7 Undervoltage Trip Ratings

Nominal Control		Pickup	Dropout
Voltage		Voltage	Voltage
	120	100	60
60 Hz AC	240 or	—	—
	480a
DC	48	40	24
	125	105	62

aNot available. Use 120 VAC undervoltage device with appropriate 240/120V or voltage transformer in cubicle.

Electrically Operated Interlock

This can be added to interlock two break- ers, preventing both from being closed at the same time. These electromechanical devices add an additional solenoid that must be energized before the breaker can be closed. When the interlock is de- energized, the breaker is held trip-free and cannot be closed electrically or manually. The interlock has a mechanical link that goes to the main shaft of the breaker. The interlock is held in the picked-up position when the breaker is closed. Once closed the interlock can be de-energized without tripping the breaker. There are no adjustments for pickup or dropout voltages. The interlocks are continuously energized.

Table 4.8 Interlock Coil Ratings

		Voltage Range
Nominal Control		Pickup	Dropout
Voltage		Voltage	Voltage
60 Hz AC	120	104	36
	240	208	72
	48	38	15
DC	125	100	38
	250	200	75

Automatic Trip Alarm Contact (with or without Lockout) (Bell Alarm)

The bell alarm contact is operated when the trip actuator operates in response to the Static Trip III trip unit. It indicates when the circuit breaker has tripped as a result of the static trip unit. The contact can control a local or remote auxiliary alarm for indication of an automatic trip or, by wiring in series with a breaker clos- ing coil, for interlocking to prevent circuit breaker closure until the circuit is reset. The contact must be reset manually or electrically (optional). The manually reset switch is available with a single-pole double-throw contact, or two single-pole single-throw contacts. The electrically reset switch is available with a single- pole single-throw contact.

If desired, a mechanical lockout option may be provided. This substitutes a manual reset for the automatically reset tripping actuator. In this case the breaker is held trip free until the lockout is manually reset.

Table 4.9 Bell Alarm Contact Ratings

Nominal		Bell Alarm Contact Ratings
		(Amperes)
Control
Voltage		Continuous	Make	Break
60 Hz	120	10.0	10.0	10.0
AC	240	10.0	10.0	10.0
	48	0.5	10.0	0.5
DC	125	0.5	10.0	0.5
	250	0.25	10.0	0.25

1	Current Sensors	3 Ground Shoe Contact	5 Secondary Disconnects
2	PT Module (Optional)	4 Primary Disconnects

RL Circuit Breaker – Rear View

58	Siemens Electrical Products and Systems	CSI Section 16470
	Specification Guide