2557 Alarm Limit Switch
The 2557 Alarm Limit Switch (ALS) provides 2 or 4 cam-operated switches for the indication of alarms or relays. It is designed to mount directly to Automatic Tank Gauges (2500 ATG) or gauge boards (6700 LLI) with an optional drive elbow. Each switch provides a contact closure (or opening) at a user-selectable position that can be used to activate alarms or relays to prevent overfills. The 2557 ALS is also designed and manufactured to provide accurate and reliable operation without an intensive maintenance schedule.
- Two SPDT cam-operated switches UL approved
- Four SPDT cam-operated switches UL/CSA approved
- Cast aluminum enclosure with o-ring seal
- Switches operable in any desired sequence
- Independent adjustment of each switch in unit
Application
The primary issues to consider when selecting the 2557 ALS product options involve the number of switch points and the height of the tank. The switches may be used to operate lamps, relays, motors or solenoid valves providing the load does not exceed ½ HP at 250 volts AC. Typically, the unit must operate over the range denoted by the height of the tank. Therefore, in most cases, the range of the unit selected is equal or greater than the tank height.
An application involving the closure of limit switches upon reaching high and low limits of tank capacity would involve two switches – one for the high set point and one for the low. Varec strongly recommends using the 2557 with a redundant independent alarm system.
Product Options
Level Range:
- 0 to 32 feet/0 to 9.7 m
- 0 to 60 feet/0 to 18.3 m
- 0 to 16 feet/0 to 4.8 m
Type of Switches
- Two Switches SPDT (UL Listed)
- Four Switches SPDT (UL Listed + CSA Certified)
