Trane Engineered Smoke Control System for Tracer Summit Fans, Verification of operation equipment

Associated equipment

Smoke dampers are ordered as a complete assembly. They are typically two-position dampers and have end switches that indicate the fully open and fully closed position. The switches are installed in the field. Dampers actuate with two types of control: pneumatic actuation and electrical actuation.

Note:

Switches that are part of the actuator do not provide an acceptable indication of actual damper travel. They only show the operation of the actuator and not the actual position of the damper.

For pneumatically actuated smoke dampers, the operating pressure range (spring range) and the normal position of the damper must be specified. Typically, the normal position will be closed (normally closed). The spring range must be high (8–13 lbs) to give the most close-off force.

Uniform Building Code 905.10.2 requires hard drawn, type L, copper pneumatic piping for smoke control system components. The air source must have automatic isolation valves separating it from pneumatic control devices not used for smoke control. Since the smoke control system will open and close smoke dampers, it may require an air pressure monitoring switch. If air pressure is lost in the smoke damper control lines, the switch transmits a Trouble indication.

For electrically actuated smoke dampers, the operating voltages are 24 Vac and 120 Vac. It is usually not possible to get actuators with DC operating voltages. A spring on the actuator positions the damper if power is lost. The power-loss position is typically the actuator closed (normally closed) position.

The electrical power that operates the smoke damper must be from an emergency power source and is monitored at a point after the last disconnect. The loss of electrical power initiates a Trouble indication.

Fans

Fans need additional control components for smoke control operation. Supply/return fan systems require independent control of fans. Multiple fan system Start and Stop points bypass some safety devices.

VAV systems require the smoke control system to be capable of either commanding the fans to full capacity or a higher capacity than comfort controls would command. High-pressure safeties are not bypassed in smoke control operation. Care must be taken to ensure that increased capacities do not trip high-pressure cutout devices. Excess pressures could deactivate fan systems, making them unusable for smoke control.

Verification of operation equipment

Codes require that the smoke control system provide verification of operation status indications at the FSCS. To accomplish this, the smoke control system provides devices that monitor the actual operation of fans

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