START UP

IMPORTANT INSTALLER NOTE

For improved start up performance, wash the indoor coil with a dishwasher detergent.

SERVICE HINTS

1.Caution owner to maintain clean air filters at all times. Also not to needlessly close off supply and return air registers. This reduces airflow through the system which shortens equipment service life as well as increasing operation costs.

2.The unit is equipped with a high pressure cut out switch.

3.Check all power fuses or circuit breakers to be sure they are the correct rating.

4.Periodic cleaning of the outdoor coil to permit full and unrestricted airflow circulation is essential.

HIGH & LOW PRESSURE SWITCH

The W12Aà models are supplied with a remote reset high and low pressure switch. If tripped, this pressure switch may be reset by turning the thermostat off then back on again.

SEQUENCE OF OPERATION

HEATING – Circuit R-Y makes at thermostat pulling in compressor contactor, starting the compressor and outdoor motor. The G (indoor motor) circuit

is automatically completed on any call for cooling operation or can be energized by manual fan switch on subbase for constant air circulation. On a call for heating, circuit R-W1 make at the thermostat pulling in heat contact for the strip heat and blower operation.

COMPRESSOR CONTROL MODULE

The compressor control module is optional on the models covered by this manual. The compressor control is an anti-short cycle/lockout timer with high and low pressure switch monitoring and alarm relay output.

Adjustable Delay on Make and Break Timer

On initial power up or any time power is interrupted to the unit the delay on make period begins, which will be

2 minutes plus 10% of the delay on break setting. When the delay on make is complete and the high pressure switch (and low pressure switch if employed) is closed, the compressor contactor is energized. Upon shutdown the delay on break time starts and prevents restart until the delay on break and delay on make periods have expired.

During routine operation of the unit with no power interruptions the compressor will operate on demand with no delay.

High Pressure Switch and Lockout Sequence

If the high pressure switch opens, the compressor contactor will de-energize immediately. The lockout timer will go into a soft lockout and stay in soft lockout until the high pressure switch closes and the delay on break time has expired. If the high pressure switch opens again in this same operating cycle the unit will go into manual lockout condition and the alarm relay circuit will energize. Recycling the wall thermostat resets the manual lockout.

Low Pressure Switch, Bypass and Lockout Sequence

If the low pressure switch opens for more than 120 seconds, the compressor contactor will de-energize and go into a soft lockout. Regardless the state of the low pressure switch, the contactor will reenergize after the delay on make time delay has expired. If the low pressure switch remains open, or opens again for longer that 120 seconds, the unit will go into manual lockout condition and the alarm relay circuit will energize. Recycling the wall thermostat resets the manual lockout.

Alarm Relay Output

Alarm terminal is output connection for applications where alarm relay is employed. This terminal is powered whenever compressor is locked out due to HPC or LPC sequences as described.

NOTE: Both high and low pressure switch controls are inherently automatic reset devices. The high pressure switch and low pressure switch cut out and cut in settings are fixed by specific air conditioner or heat pump unit model. The lockout features, both soft and manual, are a function of the Compressor Control Module.

Manual

2100-509E

Page

14 of 17

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Bard W12A2-A Important Installer Note, Service Hints, High & LOW Pressure Switch, Sequence of Operation
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W12A2-A specifications

The Bard W12A2-A is a cutting-edge piece of equipment that has gained significant attention in the industrial sector for its innovative design and advanced features. Renowned for its efficiency and reliability, the W12A2-A is an essential tool for various applications, particularly in manufacturing and performance-heavy operations.

One of the standout features of the Bard W12A2-A is its powerful engine, which provides exceptional torque and horsepower, allowing it to operate seamlessly under demanding conditions. This engine is paired with an advanced transmission system that ensures smooth and responsive acceleration, making it a preferred choice for professionals who require precision in their work.

In terms of technology, the Bard W12A2-A integrates state-of-the-art automation systems that enhance productivity and reduce operational costs. The onboard computer system is equipped with real-time monitoring capabilities, allowing users to track performance metrics and conduct diagnostics with ease. This level of intelligence not only assists in preventive maintenance but also optimizes the overall uptime of the machine.

The Bard W12A2-A also incorporates advanced safety features designed to protect operators and prevent accidents. Its robust structural design is complemented by a suite of sensors that continuously monitor the machine's performance, alerting users to any potential hazards before they escalate into significant issues. This focus on safety is critical in high-stakes environments.

Furthermore, the W12A2-A is recognized for its superior build quality, utilizing durable materials that withstand the rigors of industrial use. This ensures longevity and minimizes the need for frequent repairs or replacements, offering excellent value for investment.

Ergonomically designed, the Bard W12A2-A prioritizes user comfort, with an intuitive control panel and customizable settings that cater to a wide range of operational preferences. This thoughtful approach to design enhances the user experience and boosts overall productivity.

Overall, the Bard W12A2-A stands out in the market for its combination of power, advanced technology, safety features, and user-friendly design. Whether used in manufacturing, logistics, or any performance-based industry, the W12A2-A promises to deliver high efficiency and exceptional reliability, making it a formidable asset for any operation seeking to enhance productivity and maintain high standards.
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