FDD - Fire Detection Devices Ltd.

The second set of N/O or N/C contacts in a THERMOFLEX™ heat detector is used to activate a local ancillary function that includes elevator recall, release of magnetically-held doors, local signal operation, local annunciation, etc. In many cases this set of contacts will be connected to a controlling relay that is used to switch heavier voltages.

The model number suffix “-2”, indicates that the detectoir is a double circuit with two (2) sets of Normally Open (N/O) contacts. The model number suffix “-2C”, indicates that the detectoir is a double circuit with two (2) sets of Normally Closed (N/C) contacts. The model number suffix “-2CO”, indicates that the detectoir is a double circuit with one set of Normally Open (N/O) contacts, and one set of Normally Closed (N/C) contacts.

Double Circuit - Normally Open Contacts

The second set of N/O contacts are used to activate a local ancillary function that includes elevator recall, release of magnetically-held doors, local signal operation, local annunciation, etc.

Double Circuit - Normally Closed Contacts

The second set of N/C contacts is used to activate a local ancillary function that includes elevator recall, release of magnetically-held doors, local signal operation, local annunciation, etc.

Double Circuit - Normally Open & Normally Closed Contacts

The second set of N/C contacts is often used to activate a local ancillary function that includes elevator recall, release of magnetically-held doors, local signal operation, local annunciation, etc.

Double Circuit - N/O Contacts - Sealed

Double circuit, Normally Open (N/O) contacts detector, in which the connectivity is modified with pigtail leads that extend through a seal plate.

Double Circuit - N/C Contacts- Sealed

Double circuit, Normally Closed (N/C) contacts detector, in which the connectivity is modified with pigtail leads that extend through a seal plate. This provides for enhanced protection against corrosive or moisture-laden environments.

Double Circuit - N/C & N/O Contacts- Sealed

Double circuit detector, in which one set of contacts is Normally Open (N/O), and the other set of contacts is Normally Closed (N/C). The connectivity is modified with pigtail leads...