EXCEL 10 FCU CONTROLLER LNS PLUG-INS USER GUIDE

NV name

field name

nviManCool

nviManHeat

nviManOccCmd

nviManualMode

EN2B-0285GE51 R0909

Table C3. Input Variables for Excel 10 FCU Controllers

engineering units:

digital

 

 

state

default

comments

English (metric) or states plus

or

range

 

 

value

 

 

 

 

 

 

 

 

 

SNVT_lev_percent

 

 

This input variable can be used for master/slave installations

0 to 100%

 

 

where the cool output is controlled by an external controller node.

163.835% = INVALID

 

 

In this case, the output signal of the cooling control algorithm (0-

 

 

 

100%) of the master has to be bound to nviManCool and then

 

 

 

takes over the task of the local (slave) control algorithm while the

 

 

 

switch levels operate as locally configured. The heating output will

 

 

 

be closed.

 

 

 

 

SNVT_lev_percent

 

 

This input variable can be used for master/slave installations

0 to 100%

 

 

where the heat output is controlled by an external controller node.

163.835% = INVALID

 

 

In this case, the output signal of the heating control algorithm (0-

 

 

 

100%) of the master has to be bound to nviManHeat and then

 

 

 

takes over the task of the local (slave) control algorithm while the

 

 

 

switch levels operate as locally configured. The cooling output will

 

 

 

be closed.

 

 

 

 

SNVT_occupancy

 

OC_NUL

This input variable is from an network connected operator inter-

OC_OCCUPIED

0

(at application restart)

face or other node that indicates the state of manual occupancy

OC_UNOCCUPIED

1

 

control (schedule override). It has priority over the time program

OC_BYPASS

2

 

(nviTodEvent). When the BYPASS mode is set, the bypass time is

OC_STANDBY

3

 

active. When the bypass time has elapsed, the master controller

OC_NUL

255

 

automatically sets nviManOccCmd to OC_NUL. nviManOccCmd

 

 

 

does not provide a failure detect mechanism in case no periodic

 

 

 

update is received.

 

 

 

 

BYTE

 

MODE_ENABLE and

This input variable is used to disable the controller’s control

MODE_ENABLE

0

UNSUPPRESS_ALARMS

algorithms in order to manually set its physical outputs. The

MODE_DISABLE

1

(at application restart)

controller still responds to smoke purge even when disabled or set

MODE_MANUAL

2

 

to manual or factory test mode. It remains unchanged until another

SUPPRESS_ALARMS

3

 

mode has been commanded or an application restart has been

UNSUPPRESS_ALARMS

4

 

performed.

 

 

 

• MODE_ENABLE: starts the control algorithm at an initial state

 

 

 

after MODE_DISABLE or MODE_MANUAL.

 

 

 

• MODE_DISABLE: all outputs switched OFF, the alarm

 

 

 

ALARM_NODE_OFF is issued.

 

 

 

• MODE_MANUAL: all control loops are disabled and the alarm

 

 

 

ALARM_NODE_OFF is issued. The outputs can be controlled

 

 

 

manually via the nviTest command

 

 

 

• SUPPRESS_ALARMS: nvoAlarm is not sent and

 

 

 

nvoAlarmStatus and nvoAlarmLog are not updated until

 

 

 

UNSUPPRESS_ALARMS is set or an application restart.

 

 

 

• UNSUPPRESS_ALARMS: releases alarm suppression after

 

 

 

SUPPRESS_ALARMS.

 

 

 

 

 

 

48

 

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Honeywell W7752D Ocnul, Ococcupied, Ocunoccupied, Ocbypass, Ocstandby, Modeenable Unsuppressalarms, Modedisable
Page 49 Page 51

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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