EXCEL 10 FCU CONTROLLER LNS PLUG-INS USER GUIDE

Safety Features

Frost Protection

If the room temperature falls below 46.4 °F (8 °C), the Excel 10 FCU Controller enables the heating circuit to ensure frost protection and an alarm is issued. When the temperature rises above 48.2 °F (9 °C) again, the heating circuit is turned OFF again.

Smoke Control

The Excel 10 FCU Controller will respond to LONWORKS network emergency commands by switching OFF heating/cooling outputs and switching OFF the fan (depressurize) or switching ON the fan at its highest speed (pressurize). An alarm is issued for any emergency commands

Fan Failure Protection

When configured with an airflow detector, the Excel 10 FCU Controller protects equipment by switching OFF heating / cooling outputs and issuing an alarm when the fan fails.

Fan Interlocks

The Excel 10 FCU Controller can be configured such that heating and/or cooling outputs are never ON unless the fan is running. A fan run-up time can be configured to turn ON the fan prior to the heating/cooling outputs being switched ON, and a fan overrun time can be configured to keep the fan running for a period of time after the heating/cooling outputs are switched OFF.

Operating Modes

The possible modes of operation are listed in Table 4.

Table 4. Modes of operation for Excel 10 FCU Controller

mode

description

events causing a transition to this mode

operational modes (NV reference)

 

START-UP AND

Control algorithms are disabled. Outputs stay in

This is the first mode after an application restart.

WAIT

their initial positions. Physical inputs are periodically

 

 

read and digital filtering of analog inputs is turned

 

 

OFF to speed up settling time. Input NVs are

 

 

received and output NVs are sent periodically.

 

FLOATING

The Excel 10 FCU Controller drives the floating

When the effective occupancy changes to

OUTPUTS SYNCH

control valves to their initial positions and then

"unoccupied" or "standby", after start-up, after 24

 

transitions to one of the control modes.

hours since the last positioning, or after each

 

 

positioning to 0%, the Excel 10 FCU Controller

 

 

transitions to this mode.

COOLING

The Excel 10 FCU Controller is controlling in the

Network input nviApplicMode has a value of

 

cooling mode.

HVAC_COOL or HVAC_AUTO and the space

 

 

temperature is above the cooling setpoint.

HEATING

The Excel 10 FCU Controller is controlling in the

Network input nviApplicMode has the value of

 

heating mode.

HVAC_HEAT or HVAC_AUTO and the space

 

 

temperature is below the heating setpoint.

MANUAL MODE

The control algorithms stay active and outputs are

Network input nviManualMode has value of

 

controlled automatically until set individually to test

MODE_MANUAL.

 

positions using the input NV nviTest.

 

FACTORY TEST

Control algorithm is disabled; a special factory test

This mode is for factory testing, only.

 

program runs.

 

DISABLED

Control algorithms are terminated, outputs are

Network input nviManualMode has a value of

 

turned OFF (turn-OFF sequences and interlocks are

MODE_DISABLED.

 

active). Frost protection is disabled.

 

PRESSURIZE

Heating/cooling outputs are switched OFF, and the

Network input nviEmerg containing smoke control

 

fan is switched ON at its highest speed.

signal from the LONWORKS network has the value

 

 

of EMERG_PRESSURIZE.

DEPRESSURIZE

Heating, cooling, and fan outputs are switched OFF.

Network input nviEmerg containing smoke control

 

 

signal from the LONWORKS network has the value

 

 

of EMERG_DEPRESSURIZE.

EN2B-0285GE51 R0909

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Honeywell W7752D specifications Safety Features, Operating Modes
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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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