Response Times; Cable Distance Considerations - Trane Engineered Smoke Control System Application Manual

BAS-APG001-EN

Response times

Response times are a pre-installation consideration. For a discussion of
response time requirements for smoke control systems, refer to NFPA
92A (NFPA 2000, Recommended Practice for Smoke Control Systems),
section 3.4.3.3 and NFPA 92B (NFPA 2000, Guide for Smoke Management
Systems in Malls, Atria, and Large Areas), section 4.4.4. The activation
sequence should be accomplished so as to avoid damage to the equipment.
For example, the dampers should be opened before starting the fans.
Table 7 shows the required response times, as published in the referenced
NFPA documentation.
Table 7. NFPA response time requirements
Component
Damper operation to desired state
(open or closed)
Fan operation to desired state
(on or off)
Note:
Some building codes such as the Uniform Building Code have
much more stringent response times. As with all of the
considerations discussed in this chapter, the local authority
having jurisdiction (AHJ) has the final word.

Cable distance considerations

Table 8 on page 30 given cabling distance requirements for data of two
different types:
Hardware based, such as from analog or binary inputs and outputs
•
Communication based, such as from the Lontalk communication link
•
or I/O bus (EX2)
The table also presents different cabling distance requirements
depending on whether the data path is monitored or unmonitored.
There are no stated distance limitations for monitored information paths.
The maximum distance allowed is the same as the manufacturer's stated
maximum distance for that particular data type. A data path is
considered monitored if some notification for opens, ground-shorts, and
conductor shorts is available and used (NFPA 72A [2002] section 4.4.7.1).
Response times
Response time
75 seconds
60 seconds
29