Permanents - Johnson Controls - LIT-12014272 - Valve - Venturi Valve

Venturi Air Valve with UVM1000 Installation Guide

Brand
Johnson Controls
Product name
Venturi Valve
Document type
Installation Guide
Document number
LIT-12014272
Revision date
2023-03-10
Language
English

AI setpoint

The use AI setpoint state selects whether the CFM or positional setpoint is derived from the analog IN connection or from a value set by the configuration tool. When selected, the value is derived from the scaled analog IN value. This value is the typical mode of operation. When not selected, the setpoint value can be set via the setpoint field on the dynamic values tab. Ignore the IN voltage.

Pressure sensor as DP state

The Use press sens as DP state selects whether a connected pressure sensor is used to measure the DP across the valve. The state determines when the DP is invalid and reduces the CFM feedback signal to zero. Refer to the UVM Installation Guide for sensor wiring information. If this state is enabled, ensure the gain press sen, offset press sen, and no flow press values are valid and set. Ensure use DI as DP, use digital sensor, and unit is VAV box are not selected.

If DP monitoring is required, but a DP switch is used instead of a pressure sensor, select the use DI as DP check box and ensure the use press sens as DP check box is not selected. A calibrated DP switch monitors the pressure across the valve and makes or breaks contact when the pressure falls below the specified valve minimum operation pressure.

DP switch

The normally closed or normally open (NC/NO) mode of operation for the switch is set with the state of the DP switch NC. When checked, the DP switch is normally closed and opened when the pressure falls below the specified value.

The float DO is DP out setting enables the pressure sensor, when used to monitor DP, to report DP sensor state. This setting simulates a DP switch with a pressure sensor.

The pressure sensor and the UVM pressure settings enable the DO to act as the output of a DP switch for use on other controllers to reduce the CFM reading to zero. When the setting is selected, the floating actuator output control cannot be used. Use the pressure sensor to measure the valve DP. Ensure the use press sens as DP check box is checked.

Digital sensor

The use digital sensor enables a specific digital sensor instead of the analog pressure sensor. The digital sensor uses I2C communications media to communicate with the UVM. Ensure the setting is not checked. This is a legacy setting and may be removed in future revisions.

VAV box unit

The unit is VAV box is used to set the UVM mode to compute CFM from a VAV box flow probe instead of a Venturi valve lookup curve. Ensure the gain press sen and offset press sen fields are checked to calibrate the used pressure sensor, and the VAV box K factor and VAV box area settings are checked for proper computation of the VAV box air flow.

Ensure the use press sens as DP check box is not selected. The sensor pressure, air velocity, and air flow can be viewed under the dynamic values tab.

Minimum pressure

The Io used for min press setting applies to UVM S series revisions that provide for networked UVM units. The setting can read as being set, but can be ignored. If this UVM is a primary, it monitors the networked UVM’s DP pressure values when selected. The UVM uses pressure sensors and determines the minimum pressure value from all the units.

This scaled minimum pressure value is outputted on the IO connection on the UVM. The actuator cannot be used on this UVM. The minimum pressure value can be used by OEM control systems to regulate the fan system. The fan system is regulated to a value where the lowest valve DP is just above the minimum specified DP value for valid operation. This setting has no meaning on standalone UVMs that are not part of the summing series. This setting does not have the primary address, and can be left blank and ignored if reported as active.

Float setting

The FB (not time) float act setting applies when the UVM uses a floating actuator on the CCW and CW connections, rather than an analog actuator on the Io connector. When not checked, the floating actuator keeps track of run time in the up or down direction. For example, 50% position is an accumulated +UP, -DOWN time equal to half the fit stroke time setting. A floating actuator does not have high positional accuracy because it can slip depending on load. If the user clicks this check box, the actuator is positioned only by use of the UVM or valve FB sensor reading through the CFM table, and not by run times.

DIP switches

The use DIP switches setting derives the DIP switch equivalents from the DIP switches, or by previously set values by the configuration tool. If you select this check box is, then the CFM not Pos output, CFM not Pos input and reverse acting 2 selections are derived from the DIP switches 5, 6, and 7 settings. Ignore the settings by the configuration tool. If this box is not checked, ignore DIP switches 5, 6, and 7 and the CFM not Pos output. CFM not Pos input, and reverse Acting 2 settings are as set by the configuration tool.