EXCEL 10 FCU CONTROLLER LNS PLUG-INS USER GUIDE

Fig. 9. Three-speed fan switching and hysteresis, cooling mode (defaults for switching levels shown)

Type of Heating and Cooling Equipment

Excel 10 FCU Controllers can operate with either two-pipe or four-pipe systems. A two-pipe system requires a changeover input to the controller (hardware or network input).

Excel 10 FCU Controllers can operate with a variety of actuators for heating and cooling equipment. Floating actuators can be used; this requires that the valve run time be specified during configuration of the controller.

The actuator runtimes can be configured in the range 20 sec to 600 sec in steps of 1 second.

Valves will be synchronized by driving the valve fully closed

(150% of the valve run time) under the following conditions:

•whenever the control level reaches 0% or less;

•at power-on;

•whenever the occupancy status changes to a lower mode, e.g., from occupied to standby or unoccupied;

•when synchronization has not taken place within the last 24 hours.

Once synchronization has been completed, the output control will be returned to the normal control loop.

Valve action can be configured as either direct or reverse. When in a two-pipe system with a changeover input, a floating actuator can be used which has the middle position (50%) as the zero energy position. The cool range is then 0 to 50% and the heat range 50 to 100%. The output must be configured as floating-mid.

Multi-stage systems can be controlled with up to three different stages of heating/cooling control. Switching levels are specified in % of control level (see Fig. 10) as is a hysteresis setting which applies to all switching levels. Heating and cooling switching levels and hysteresis are specified separately. Min. OFF times can be configured, and for one-, two- and three-stage systems, a min. ON time can also be configured.

PWM electronic valves and thermal actuators can also be connected and can be configured as either direct or reverse action. The cycle time must be specified during configuration. In the case of PWM valves, the zero and full positions must also be configured.

Additionally, the W7754K1001 features an extra socket (located to the left of the terminal blocks) containing a digital output suitable for connection to a solid-state relay employed for low-voltage PWM control in high-current electric reheat applications.

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EN2B-0285GE51 R0909

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Honeywell W7752D specifications Type of Heating and Cooling Equipment
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W7752D specifications

The Honeywell W7752D is a versatile and advanced electronic gas combination control designed primarily for use in commercial heating systems. This product stands out for its ability to manage both gas ignition and safety functions, which are critical for maintaining the efficiency and safety of heating appliances. Its robust construction and advanced features make it a popular choice for HVAC professionals and service technicians.

One of the main features of the W7752D is its integration of multiple functions in a single device. It serves as both an automatic gas ignition control and a safety shut-off valve, which simplifies installation and reduces the need for additional components. This integrated design not only enhances reliability but also streamlines maintenance procedures.

Another notable technology utilized in the W7752D is its microprocessor-based control logic. This advanced technology allows for precise management of the ignition sequence, improving the overall efficiency of the heating system. The microprocessor enables the control to adapt to varying operating conditions, ensuring optimal performance even under changing demands.

The W7752D is equipped with features that enhance user-interface and diagnostics capabilities. It includes LED indicators that provide clear information about the operational status and any potential issues. This diagnostics capability facilitates easier troubleshooting, saving time and reducing the likelihood of extended downtimes.

Safety is a primary concern in gas appliances, and the W7752D addresses this with built-in safety mechanisms, including flame detection technologies. These features ensure that the appliance operates safely, automatically shutting down in case of any irregularities during operation. This emphasis on safety not only protects property but also provides peace of mind for users.

In terms of compatibility, the Honeywell W7752D is designed to work with a wide range of gas heating appliances. Its flexibility allows it to be used in various applications, making it suitable for different types of commercial environments. Additionally, the control complies with relevant safety and performance standards, ensuring reliable operation.

In summary, the Honeywell W7752D combines advanced technology with essential safety features, making it a top choice for commercial heating applications. Its integrated design, microprocessor-based control, user-friendly diagnostics, and robust safety mechanisms make it an essential component for efficient and safe gas heating systems. Whether it is for new installations or replacements, the W7752D provides HVAC professionals with the reliability and ease of use they demand.
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