BAC Custom Engineered Controls

Features and Options

Variable Frequency Drives (VFDs)

NEMA 12 VFD with Bypass and Multi-Monitor Display

Multi-Monitor Display and Keypad

VFDs offer many benefits including:

(1) Precise leaving fluid temperature control provides a more efficient method to vary airflow compared to fan cycling, fan dampers, or mechanical speed changers.

(2) Soft-starts, stops, and smooth accelerations prolong the mechanical system (fans, motors, belts, bearings, etc) life while reducing maintenance.

(3) The soft-start feature minimizes start-up noise and smooth acceleration make the tower sound less noticeable to the neighbors.

The VFDs are UL 508C listed and CUL certified and are provided with a standard two year warranty.

Standard

• VFDs include an enclosure, 24VDC power supply, control power transformer, main circuit breaker, disconnect switch with lockable operator handle, 3-contactor bypass, modular cooling fan and a detachable, programmable VFD keypad.
• 3-Contactor Bypass is standard on all BAC drives. The input contactor electrically isolates the drive during bypass operation. The output and bypass contactors are mechanically interlocked to regulate power to the fan motor. Bypass allows for 100% fan speed operation back-up if the drive is not functional for any reason.
• Circuit Breaker Protection, which allows for quick reset, is standard on all BAC VFDs. The circuit breaker is mechanically linked to the rotary disconnect switch mounted on the front of the panel.
• User Interface Keypad controls hand-off-auto and bypass modes. The multi-monitor display shows fan speed, set point, measured temperature/pressure, vibration warnings and fault codes.
• Custom VFD Software has been developed for typical applications. The BAC Start-up Wizard guides the operator step-by-step through the required parameters and useful settings.

Optional

Communications Cards can be provided when a Building Automation System is used. Currently, BAC offers Modbus, Lonworks and Johnson N2 cards. Consult the factory for BACNet and Siemens communication card availability.

Commissioning is available to ensure successful configuration and operation of BAC drives. Completion of factory authorized start-up will extend the standard warranty from two to three years, including parts and labor.

Enclosed Controls

Standard Panel with Fan Motor Starter

BAC enclosed controls, designed with the highest grade components, are packed with operation-friendly features to ensure a long life expectancy and lower life cycle costs. The modular design of BAC panels allows for consistency across projects and simplifies upgrades or future replacements, yet can be customized to meet your particular application. The enclosed controls are UL 508A listed and CSA/CUL certified and are provided with a standard one year warranty.

Standard

• Panel with Fan Motor Starter(s) includes an enclosure, control power transformer, main circuit breaker, disconnect switch with lockable operator handle, hand-off-auto switch, run pilot lights for each starter, and full voltage, non-reversing starter with overload relay and double-break silver alloy contacts.
• Circuit Breaker Protection allows for quick reset and is standard for all BAC control panels. The main circuit breaker is sized for the maximum current draw for the panel configuration. Each fan motor starter includes individual branch circuit protection.

Optional

• Electric Water Level Control Interface includes wired interlock to the solenoid make up valve and provision for high and low level alarms.
• Fan Motor Starters are available for two speed/one winding; two speed/two winding or main/pony motor configurations such as the ENERGY-MISER® Fan System.
• Basin Heater Controls are equipped with definite purpose contacts, a resettable short circuit protection device, ground fault protection, Hand-Off-Auto switch, and run pilot light. Basin heater controls include Ground Fault Interrupt Protection as required by NEC Article 427.
• Spray Pump Motor Starter(s) include full voltage, non-reversing starter with overload relay and double-break silver alloy contacts.
• Positive Closure Damper Interface includes wired interlock to the fan motor starter.
• Temperature/Pressure Controller & Interface Package includes a temperature or pressure sensor with a 4-20mA transmitter to modulate the fan speed and perform other functions such as: turn heaters on and off, turn the spray pump on and off, or open and close dampers based on a factory programmed sequence of operation.

Safety Disconnect Switches

NEMA 4X Safety Disconnect Switch

Since control panels can be installed in indoors, NEC Article 430-102b requires a disconnect switch located within sight of the motor and the driven machinery location. BAC safety disconnect switches are rated for 600 VAC and sized specifically for the current draw of the components. The safety disconnect switches are UL E239 listed and CSA certified and are provided with a standard one year warranty.

The Safety Disconnect Switch meets the NEC requirements and includes an enclosure, knife blade style contacts, door lock provision, interlock, ground lug and a clear line shield.

Other Options

Externally Mounted Factory Pre-wired Terminal Box
(Currently available only on Series 3000 Cooling Towers)

Factory Wiring to the Fan Motor & Vibration Cutout Switch to the Terminal Blocks

As an option, all wiring for the fan motor(s) and vibration cutout switch leads are pre-wired from the factory and terminated on the outside face of the BAC unit in a clearly marked terminal box. This feature saves installation labor required to run conduit and wiring to the motor and vibration cutout switch, while saving material costs for the internal conduit, wire, couplings and hardware. The externally mounted terminal boxes are UL 1773 listed and CSA certified. The externally mounted terminal boxes are provided with a standard five year warranty. The Terminal Box includes a factory-mounted enclosure, factory wiring to terminal blocks for the fan motors and vibration cutout switches, and grounding lugs.

Universal Mounting Brackets
Optional Steel struts and mounting hardware are provided for simple field installation of the control panels. The universal mounting brackets are provided with a standard one year warranty. Standard Universal Mounting Brackets include universal mounting hardware for location flexibility and adjustable vertical position panels.