Greenheck Vari-Green Control User Manual

Document 479653

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Generation 2

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Constant Pressure/Air Flow Control

Installation, Operation and Maintenance Manual

Please read and save these instructions for future reference. Read carefully before attempting to assemble, install,
operate or maintain the product described. Protect yourself and others by observing all safety information. Failure
to comply with instructions could result in personal injury and/or property damage!

Remote

Transducer

Controller with
Integral Transducer

Controller with
Remote Transducer

Precautions and Warnings

To prevent injury and property damage, follow these
instructions. Failure to adhere to installation/operation
procedures and all applicable codes may result in
hazards as indicated by warning codes outlined below:

DANGER

Indicates an imminently hazardous situation which,
if not avoided, will result in death or serious injury.
This signal word is to limited to the most extreme
situations.

WARNING

Indicates a potentially hazardous situation which, if
not avoided, could result in death or serious injury.

CAUTION

Indicates a potentially hazardous situation which, if
not avoided, may result in minor or moderate injury. It
may also be used to alert against unsafe practices.

This is the safety alert symbol. Read and
follow instructions carefully to avoid a
dangerous situation.

This symbol alerts the user to the presence
of “dangerous voltage” inside the product
that might cause harm or electrical shock.

Table of Contents

Constant Pressure Control .................. 2

Installation ........................................... 2

General Operation .......................... 3 - 5

Initial Setup Menu Structure ................ 6

Setpoint Edit Menu Parameters .......... 7

Initial Setup Menu Parameters ............ 8

Wiring Diagrams Overview ............. 9-10

Part Number Table ............................. 10

Air Density Correction Factors .......... 11

Specifications .................................... 11

Assembly Part Numbers .................... 11

Mounting Hole Pattern ...................... 11

Safety Instructions

DANGER

Equipment can start automatically. Lockout/tagout
before servicing.

CAUTION

As with all electrical products, read manual
thoroughly. Only qualified, expert personnel should
perform maintenance and installation. Contact the
nearest authorized service facility for examination,
repair, or adjustment. Do not disassemble or repair
unit unless described in this manual; death or
injury to electrical shock or fire hazard may result.
Specifications and manual data subject to change.
Consult factory for additional information.

DANGER

HAZARDOUS VOLTAGE

• Disconnect and lock out all power before installing
or servicing equipment.

• This equipment may require locking out multiple
power sources prior to service.

• Install and wire in accordance with all applicable
local and national electrical and construction codes.

WARNING

FAILURE TO FOLLOW THESE INSTRUCTIONS
MAY RESULT IN DEATH OR SERIOUS INJURY.

Constant Pressure Control 1

Constant Pressure Control

The Greenheck Constant Pressure Control is designed
to maintain a constant level of static pressure or airflow
by automatically adjusting the speed of a fan or position
of damper. The Constant Pressure Control output is
compatible with the Vari-Green® Motor, many variable
frequency drives (VFDs), or dampers with modulating
actuators.

The Constant Pressure Control is available with duct
or room mounted probes for static pressure control,
as well as a pitot tube or Greenheck’s AMS (Airflow
Monitoring Station) for maintaining airflow. Common
applications include:

• Multi-story

• Variable volume exhaust systems serving bathrooms

• Residential kitchen hoods or clothes dryers

• Room pressurization and filtered supply/exhaust
where constant airflow is required as the filters
become dirty

Receiving

Upon receiving the control, check to ensure all items
are accounted for by referencing the delivery receipt or
packing list. Inspect each crate or carton for shipping
damage before accepting delivery. Alert the carrier
of any damage detected. The customer will make
notification of damage (or shortage of items) on the
delivery receipt and all copies of the bill of lading which
is countersigned by the delivering carrier. If damaged,
immediately contact your Greenheck Representative.
Any physical damage to the unit after acceptance is not
the responsibility of Greenheck Fan Corporation.

Unpacking

Verify that all required parts and the correct quantity of
each item have been received. If any items are missing,
report shortages to your local representative to arrange
for obtaining missing parts.

Storage

Controls are protected against damage during
shipment. If the control cannot be installed and
operated immediately, precautions need to be taken
to prevent deterioration of the control during storage.
The user assumes responsibility of the control and any
accessories while in storage. The manufacturer will
not be responsible for damage during storage. These
suggestions are provided solely as a convenience to the
user.

Indoor - The ideal environment for the storage of control

is indoors, above grade, in a low humidity atmosphere
which is sealed to prevent the entry of blowing dust,
rain or snow. Temperatures should be evenly maintained
between 30° to 110°F (-1° to 43°C). Wide temperature
swings may cause condensation and “sweating” of
metal parts. All accessories must be stored indoors in a
clean, dry atmosphere.

Removing from Storage

As controls are removed from storage to be installed
in their final location, they should be protected and
maintained in a similar fashion until the control goes into
operation.

Installation

Parts Needed

• Control voltage wiring – 18-20ga recommended

• Pressure tubing – 1/4 inch (6mm)

• Fasteners for mounting

• Conduit fittings (1/2 inch (13mm) NPSM)
Note: Mounting hole pattern for controller and

transducer on pg. 11.

Controller – Integral Pressure Transducer

The controller with integral pressure transducer is a
NEMA-4 rated enclosure. Mount the controller in a
location where it can be accessed for programming and
status viewing. The controller should be mounted in an
environment where the temperature remains between
45° and 80° F. (7° and 27°C). This temperature range
is due to the temperature compensation range of the
integral pressure transducer. If the controller needs to
be mounted in a location that will routinely exceed this
range, the controller that accepts a remote transducer
should be used.

The controller should be mounted with the hinge of the
door on top. Keep in mind wiring and tubing lengths
when selecting a location.

Controller – Remote Pressure Transducer

The controller with remote pressure transducer is used
for applications where the controller must be mounted
in areas where the temperature may exceed the
compensation range of the pressure transducer.
Both the controller and remote pressure transducer are
in a NEMA-4 rated enclosure. The pressure transducer
should be mounted in an environment where the
temperature remains between 45° and 80°F

(7° and 27°C)

Maximum Recommended Distances

Tubing Wiring
Probe to Transducer 100 feet (30.5m) N/A
Transducer to Controller N/A 200 feet (61m)
Controller to Fan/Motor/VFD N/A 100 feet (30.5m)

Conduit Fittings

Connections - A stepped drill bit can be used to create
openings in the conduit fittings. Take care to not
damage the components inside the housing
when drilling.

Pressure Probes

A duct static, room static, 2-piece pitot tube and AMS
are available from Greenheck. Other pressure probes
may be used as well.

Duct Static Probe (FIG. 1)

The duct static probe must be located in the duct where

Constant Pressure Control2

FIG. 1

you intend to control the static
pressure. It should be located
a minimum of 10’ away from
the inlet/outlet of the fan/
damper to ensure stable
operation.

The duct static probe is always
connected to the “H” port
of the control/transducer.
The “L” port is the reference
port and can remain open to

atmosphere or plumbed to another location.

General Operation

Controller with Integral Transducer

H Pressure Port

Display

Enter Button

Auto Zero Button

PROG/RUN Switch

Room Static Probe

The room static probe is used to sample the pressure in
an open space such as a room or hallway. The pressure
controlled room must be connected to the “H” port. The
“L” port is the reference port and can remain open to
atmosphere or plumbed to another location.

Alternatively, if the controller/transducer is mounted
in the space in which the pressure is to be controlled,
the “H” port can remain open and the “L” port must be
plumbed to another location for reference.

2-Piece Pitot Tube

The 2-piece pitot tube consists of a total pressure (PT)
probe and a static pressure (PS) probe. These probes
should be mounted in a straight section of ductwork
located away from elbows or transitions. The total
pressure probe can be identified by a 45deg. cut at the
end and the arrow identifying airflow direction on the
mounting flange.

Examples for mounting the probes are shown in FIG. 2
(A, B, C).

AIR FLOW

(102-203mm)

PT S

AIR FLOW

4-8 in.

P

(A)

FIG. 2

CORRECT

Back Button

L Pressure Port

Controller with Remote Transducer

Up Arrow

Remote Transducer

Status LED

Down Arrow Enter Button

Pressure

Down Arrow

Up Arrow

DisplayBack Button

Control Wiring

Connector

Romote Transducer

Wiring Connector

Control Wiring

Connector

Wiring Connector

Power Wiring

Connector

PROG/RUN

Switch

Power Wiring

Connector

(B)

(C)

INCORRECT

CORRECT

2-4 in.

AIR FLOW

(51-102mm)

SP

PT

SP

PT

12 in.

(305mm)

OR GREATER

Connect the total pressure probe to the “H” port of the
control/transducer and the static pressure probe to the
“L” port.

AMS (Airflow Measuring Station)

The AMS should be mounted away from elbows and
transitions. Connect the “HIGH” port of the AMS to the
“H” port and the “LOW” port of the AMS to the “L” port
of the control/transducer.

H Pressure Port L Pressue Port

Auto Zero Button

Display

The 2-line multi character display is backlit and is
used to read the status of the control as well as setting
parameters during programming.

Touch Buttons

The buttons on the front of the control are touch
sensitive, similar to the touch screen of a smartphone.
Gloves must be removed to ensure it senses your finger.
In RUN mode, the arrow buttons can be used to display
different process variables. In PROG mode, the arrow,
enter and back buttons are used to navigate the menus
and set parameters. When using the arrows to set
parameters, holding the button down will increase the
scrolling speed.

Constant Pressure Control 3

LED Status

Output: XX.X%

Flow: XXXXX CFM

Dp: X.XX in WC

Flow: XXXXXX CFM

If control mode=

Constant
Pressure

If control mode=
Constant Airflow

Vel: XXXXX FPM

Flow: XXXXXX CFM

If control mode=

Constant Airflow

A status LED exists on the control and remote pressure
transducer.

Control:

Transducer:

Pressure Transducer Auto Zero

The integral and remote pressure transducer includes
an auto zero function. There is an auto zero button on
the inside of the enclosure. If the controller is already
installed, remove field tubing and connect the “H” and
“L” port of the pressure transducer together with a
short piece of tubing (Fig. 3). Press the auto zero
button inside the
enclosure. When
the LED stops
flashing, remove
the tubing and
reconnect the
existing field
tubing.

Inputs/Outputs

The controller contains the following inputs/outputs:

Inputs:

Outputs:

Green = Normal Operation
Pink = Programming/manual mode
Flashing Yellow = Cutout timer is active
Solid Yellow = Cutout mode is active
Red = Override active

Red = >1.00 in.WC (>249Pa)
Green = 0 —1.00 in.WC (0-249Pa)
Yellow = 0 in.WC (0Pa)
Blue = 0 — -1.0 in.WC (249Pa)
Pink = < -1.00 in.WC (249Pa)

FIG. 3

Pressure tubing connected for auto zero

Remote Override (digital, dry contact)

• Activating this input will force the Fan Speed
output to a fixed % (adjustable)

Remote Setpoint (analog, 0-10V or 2-10V)

• A voltage signal can be sent to the control to
remotely adjust the setpoint.

Remote Transducer (analog, 0-10V)

• Not available on controller with integral
transducer.

Fan Speed (analog, 0-10V, 2-10V)

Pressure/Airflow Reference (analog, 0-10V)

• The output will send the actual pressure/airflow
value to another device, such as BMS.

Relay (digital, 0.5A rating)

• The relay output will close when the Fan Speed
output is above a set % (adjustable). Common
uses are to signal a dirty filter in airflow mode or
signal another device that the fan is being called
to run.

Constant Pressure Control4

RUN/PROG Mode

Run and Program mode are set using the selector
switch on the inside of the control. Open the control
enclosure to access the switch.

RUN Mode

This control has two major functions – constant
pressure mode and constant airflow mode.

(Set using initial set up menu. pg. 6 & 7)

Constant Pressure Mode - the control will
automatically adjust the speed of the fan to maintain a
constant static pressure in a duct or room.

The display will show the following variables
(touch the arrow buttons to change the display):

Static Pressure Reading

Output %

Pressure Setpoint

Cutout Threshold %

Cutout – The following definitions will be used to
provide clarity in the explanation of the cutout feature.

Primary Fan:
The controller is connect to this fan.
Secondary Fan:
Any fan, other than the primary fan, that

influences the pressure in the system

The cutout feature is available to turn the primary fan off
in times of no demand from the secondary fans.

There are three parameters related to the cutout
function: Cutout %, Cutout Delay Time and Return from
Cutout Pressure Setpoint.

Cutout mode is activated when the fan speed
output % is less than the cutout % setpoint. After the
Cutout Delay Time has elapsed, the control will turn the
output OFF.

A change in system pressure is needed to turn the
output back ON. This value is adjustable to prevent false
pressure fluctuations from turning the fan back on.

Constant Airflow Mode – the control will automatically
adjust the speed of a fan to maintain a constant airflow
rate in a duct.

The display will show the following variables(touch the
arrow buttons to change the display):

Airflow Reading

Output %

Differential Pressure

Reading

Velocity Reading

Airflow Setpoint

Ps: -X.XX in WC
Output: XX.X%

Ps: -X.XX in WC
Set: -0.10 in WC

Ps: -X.XX in WC
Cutout: 20.0%

Flow: XXXXX CFM
Output: XX.X%

Flow: XXXXXX CFM
Dp: X.XX in WC

Flow: XXXXXX CFM
Vel: XXXXX FPM

Flow: XXXXX CFM
Set: XXXXX CFM