EXCEL 10 FCU CONTROLLER LNS PLUG-INS USER GUIDE

Configurations

General

The following sections provide an overview of the Excel 10 FCU Controller options related to inputs and outputs. See Application Step 6. Plug-Ins Configuration Screens for complete list of configuration options and defaults.

Table 7. Hardware options summary

option

 

possible configurations

fan type

no fan

 

one-speed

 

two-speed

 

three-speed

fan interlock

enabled

 

disabled

FCU system type

two-pipe

 

four-pipe

output 1 actuator

floating

type

floating mid (one for heat/cool)1

 

one-stage

 

two-stage

 

three-stage

 

PWM

 

thermal

output 2 actuator

floating

type

floating mid (one for heat/cool)1

 

one-stage

 

two-stage

 

three-stage

 

PWM

 

thermal

valve direction

direct

 

reverse

reheat

none

 

reheat (W7752D and F and

 

 

W7754P1000, only)

 

free use (W7752D and F and

 

 

W7754P1000, only)

digital input

not used

 

window closed

 

occupied sensor

 

air flow detector

 

cool changeover

 

window open

 

unoccupied sensor

 

no air flow

 

heat changeover

 

movement

 

no movement

wall module option

local

shared

temperature sensor none

type

NTC non-linearized

NOTE:

 

1The floating-mid option is only for changeover applications and uses only one of the two outputs.

Fan Type

Each fan coil unit controlled by an Excel 10 FCU Controller can have a fan with up to three different speeds or no fan at all. Multi-speed fans are switched at the same switching levels as multi-staged heating control points (see Fig. 9). For example, a three-speed fan will switch ON its first speed at the same control level as the first stage of heating or cooling up until the second stage of heating or cooling where the second fan speed will switch on. A two stage fan will switch with the first two stages of a 3-stage heating or cooling system. Likewise, a single speed fan will turn ON at the first stage of any multi-staged system. Conversely, a multi-speed fan may follow multiple switching levels even for single- staged, floating, PWM, or thermal actuator-based systems.

Hysteresis

The hysteresis for fan speed extends to the next lower switching level (or a control level of 0) as is shown in Fig. 9. For example, the second fan speed will remain ON until the control level falls below the switching point for the first fan speed. Minimum ON/OFF times can be configured and will apply to all fan switching points.

Interlock

A fan interlock can be configured which prevents heating or cooling outputs from being turned ON in the event of a fan failure (where an air flow detector is installed to detect fan failure). When fan interlock is configured, run-up and overrun- times can be configured to delay switching ON the heating or cooling equipment after switching ON the fan and delay switching OFF the fan after the heating or cooling equipment is switched OFF.

The fan can be configured to run continuously during the zero energy band during occupied periods.

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Honeywell W7752D specifications Configurations, General, Fan Type

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.