What is a UL924 relay?

The UL924 Automatic Load Relay (ALCR1277) allows the emergency lighting in a space to be controlled along with the normal lighting while ensuring that the emergency lighting will be forced to full bright upon loss of normal power to the space.

What is a shunt relay?

Hubbell Control Solutions enclosed bypass Shunt Relays are typically used to bypass a normal control such as a switch, dimmer, or panel mounted relay when used on an emergency circuit. The normally closed relay in the UL924SR1/UL924SR2 connects to the line and load side of the control device.

What is an emergency shunt?

Legrand’s Emergency Shunt Relay can simultaneously bypass both a line voltage switch and a 0-10V dimming signal, ensuring that an emergency fixture illuminates at full brightness during a utility power interruption.

How does a UL924 device work?

UL 924 devices are meant to be used in applications that take place downstream of a UL 1008 device. They are often used to bypass a wall switch or override a dimming signal on your emergency circuit in the event of normal power loss.

What is a load control relay?

Overview. The Automatic Load Control Relay (ALCR) is a UL 924 listed device that is powered from an emergency source and provides power to emergency lighting load(s). The ALCR ensures a “lights on state” during loss of normal power while tracking the state of normal lighting loads during normal operation.

What is a shunt trip disconnect?

A shunt trip device is an optional accessory in a circuit breaker that mechanically trips the breaker when power is applied to the shunt trip terminals. The power for the shunt trip does not come from within the breaker, so it must be supplied from an external source.

How does a shunt work?

How does a shunt work? A shunt is a low-ohm resistor that can be used to measure current. Shunts are always employed when the measured current exceeds the range of the measuring device. The shunt is then connected in parallel to the measuring device.

What is a ul1008 device?

UL 1008 devices are often called transfer switches. Transfer switches are used to transfer the power source of the emergency circuit from normal power to back-up power in the event of normal power loss. Typically, these are large and used to switch over entire buildings to back-up power.

What does a ripple relay do?

Ripple relays at consumer sites are programmed to respond to one or more of these channels. This gives network companies the ability to control blocks of hot water systems according to different timetables or real-time needs.

What is Master control relay?

The master control relay MC 1 acts only over the region between the rung it is designated to operate from and the rung on which MCR 1 is located. With a Mitsubishi PLC, an internal relay can be designated as a master control relay by programming it accordingly.