provide smooth modulating control under design flow and pressure conditions.
2.Valve actuators shall provide tight close-off at design system pressure. Modulating actuators shall provide smooth modulation at design flow and pressure conditions.
3.Provide feedback transmitters and/or end switches where specified.
4.Actuators shall be specified per the Control Sequences section.. Actuators relying on batteries are not acceptable.
2.14SAFETY CONTROLS
A.Freezestats: Shall be UL-listed, manual reset type, with 20-foot, non-averaging elements and auxiliary contacts for alarm purposes. Any one foot of element sensing a temperature below setpoint shall trigger fan shutdown. Provide one freezestat for each coil section of each coil bank (e.g., one coil with three sections requires three freezestats). Wire freezestats to protect unit in both hand and automatic operation. Wire one set of contacts directly to the fan starter circuit and the other to an alarm input.
B.Smoke Detectors: Specified to be furnished under Division 16 and mounted by this Con- tractor. This Contractor shall install smoke detectors for HVAC systems where called for in sequence of operation, installed per NFPA, IBC, and/or local codes. All smoke detectors shall be UL-listed for intended service. Detector shall provide isolated SPDT control interlock contact rated for pilot duty service (125 VA minimum), as well as separate alarm and trouble contacts suitable for remote monitoring by Division 16.
1.Smoke detectors located in air handling units or ducts shall be complete with duct- mounting accessories as recommended by manufacturer.
2.This Contractor shall be responsible for all smoke detector interlock wiring to HVAC equipment.
3.Wire smoke detectors to shut down the equipment in 'hand' and 'automatic' mode.
C. Emergency-Stop Switches: Emergency-stop switches and emergency-ventilation switches shall be normally closed, break-glass type with red case, located where shown on plans or where directed by Fire Marshall. Switch function and system controlled shall be clearly identified at switch location.
D. High-static Safety Switches: Shall be UL-Listed, manual reset type and shall have auxiliary contact for alarm. Wire High-static safety to protect unit in both hand and automatic
operation. Wire one set of contacts directly to the fan starter circuit and the other to an alarm input as a dry contact.
PART 3 - EXECUTION
3.01CONTROL-AIR PIPING
A. All control-air piping shall be concealed, except in equipment rooms or unfinished areas.
