Model 908A
2 Channel Over–Temperature Detector with Advance Warning
GENERAL OVERVIEW:
The 908A Over-Temperature Detector can be used to monitor two temperature readings*, either fluid or air +50°F – +300°F / +15°C – +150°C.
The Model 908A warns the trip point is approaching with a flashing signal.
When the trip point has been reached, a relay internal to the module becomes energized (failsafe) and the flashing warning signal becomes solid. The Relay is a SPST, (10 Amp Max.) with all contacts brought out to the user.
FEATURES & OPERATION:
The Over-Temperature Detector (908) is designed to operate from a 24V DC power, but will accommodate supply voltage as low as 15V DC, and as high as 28V DC.
Temperatures are monitored by the temperature sensor whose output is compared inside the Module (908A) electronics to a trip point, factory preset to user requirements.
There is a unique Pre-Alarm temperature warning point per channel. If the temperature rises above the trip point setting, the channel indicator (LED) will be off, and the internal relay will energize, closing relay contact terminals 4 and 6 (with 5 open).
When the temperature increases within approx. 2° of the trip point, the appropriate channel indicator output starts to flash. Flashing continues until the temperature falls back below the pre-alarm reset point (indicator off). If the temperature continues to increase to the trip point, the channel indicator (LED) turn on steady (indicating a trip) and the Relay is de-energized, closing contacts 4 and 5 (with 6 open).
The enclosure is Extruded Aluminum with Mounting Flanges, with 0.060 Aluminum Covers.
Units may be returned to the factory to have the temperature alarm points reset anytime during the first 2 years at no charge. $25 service charge thereafter.
There is no connection from the Case to the PC Board (Isolated).
