Eaton PowerXL DH1 User manual

Application Paper Effective March 2019
Damper control using PowerXL DH1 Variable Frequency Drives
Overview
1) During Normal electronic start, Auto and Hand
2) Normal electronic Bypass
3) Bypass mode during Emergency Faults, damper is manually operated.
References:
Description of Operation for each mode:
1) Normal electronic start, Auto and Hand (Local): Sequence of events during this mode:
a. Drive in this mode is controlled in local or remote mode from the drive keypad, with
powers the damper motor to turn the damper.
c. The motion complete of the damper will close the contact DPR-K1, acknowledging
that the damper motion is complete.
d. Closure of the damper position feedback contact DPR-K1 will also pick-up relay R1,
closing the contact R1-K1
e. Closure of DPR-K1 will get the RUN ENABLE to drive, as P2.2.19 is set to DigIN: 8.
f. With SW1 in VFD position, RUN ENABLE active the drive can be controller to the
required speed reference.
1) PowerXL DH1 Series VFD application manual MN040041
2) PowerXL EHB, EHC, EHD Enclosed installation manual IL040052EN
SW1 in VFD position
b. When start command is issued to the drive, Relay (RO3) on the drive closes, which
Damper operation with the HVAC applications is a very common requirement, where the
application requires opening the damper BEFORE starting the HVAC fans. This application note
covers damper operation and damper interlock with the DH1 drive in three different modes:
3) Interlock Delay : This mode can be used in two instances:
Eaton DH1 supports 3 different modes for damper control. Each mode offers slightly different
sequence of events in terms of the drive control philosophy.
1) Interlock Start : This mode is a basic damper control mode where drive controls look for
damper position feedback to put drive into run enable. In an unlikely event of failure to get the
damper position feedback the drive doesn't take any further action.
2) Interlock Tout : This mode is used when user would wants drive to fault, in an unlikely
event of failure to get the damper position feedback after a preset time delay.
3.a) When the user does not have a position feedback sensor on the damper and
would like to delay the drive run enable for a preselected time delay, giving enough
time for damper to change the position.
3.b) When the damper position feedback is spurious and user wants drive to ignore the
position feedback (till the issue is fixed) and have drive go to run enable after a
preselected time delay.

P13.1.2 Application 0 2 = Advanced
P2.2.19 Run Enable 19 = DigIN: 8
P2.1.1 Damper Start 01 = Interlock Start
P2.2.27 Auto Control 90 = DigIN:NormallyOpen
P3.1.8 RO3 Function 335 = Damper Control
Code Parameter Default Application Setting
Code Parameter Default Application Setting
P13.1.2 Application 02 = Advanced
P2.2.19 Run Enable 19 = DigIN: 8
P2.1.1 Damper Start 02 = Interlock Tout
P2.1.2 Damper Time Out 5
Delta normally taken by damper to close the position
feedback)
P2.2.27 Auto Control 90 = DigIN:NormallyOpen
P3.1.8 RO3 Function 335 = Damper Control
Code Parameter Default Application Setting
P13.1.2
Application 0 2 = Advanced
P2.2.19 Run Enable 19 = DigIN: 8
P2.1.1 Damper Start 03 = Interlock Delay
P2.1.2 Damper Time Out 5
User Defined Time in Seconds ( Recommendation: Time +
Delta normally taken by damper to close the position
feedback)
Interlock Delay: Drive waits for the RUN ENABLE (Damper open position feedback) because
drive Damper start has been programmed for interlock delay, like interlock start/Tout. Except in
this case drive will not start until the Damper Delay time has lapsed.
Interlock Tout: Drive waits for the RUN ENABLE (Damper open position feedback) because
drive Damper start has been programmed for interlock Tout, like interlock start. Except in this
case if the end switch is not made by the time Damper Time Out times out, the drive will fault
with message “Start-up Prevent”.
P2.2.27 Auto Control 90 = DigIN:NormallyOpen
P3.1.8 RO3 Function 335 = Damper Control
2) Normal electronic Bypass: Electronic Bypass mode for the drive is when the VFD’s
microprocessor (MCU) is used for initiating the close command to the bypass contactor
using the Bypass relay of the drive. Since the drive MCU is active, the damper control
interlock is still available through drive controls due to the parameter settings discussed
above. Based on the scheme in Figure: 2 there are two ways to initiate electronic Bypass
Below are the recommended drive parameter settingsfor Damper control. These damper control
parameters are to be set in addition to standard drive commissioning parameters for the
application.
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Interlock Start: Drive waits for the RUN ENABLE (Damper open position feedback) because
drive Damper start has been programmed for interlock start. If damper startis left at default setting
NORMAL, the damper will have to be closed before the issuing drive start CMD.

Damper control using PowerXL DH1 Variable Frequency Drives
Application Note
Effective March 2019
2.A) SW1 set to VFD position: The sequence of events:
a. The SW1 on the drive enclosure/panel is set to VFD position.
b. The BYPASS start is triggered from the Drives keypad. Optionally the switch on the
panel/enclosure wired to DI7 (Optional switch not shown in Figure:2).
c. The step b above will put the drive in Bypass mode (see Figure 1).
d. Trigger the start command to the drive like the start command to the drive in VFD
mode.
e. The start command to the drive will trigger RO3, initiating the damper motion.
f. After the damper position feedback is received the drive will close RO1, closing the
Bypass contactor and starting the motor.
Figure: 1 Showing Drive in Bypass mode
2.B) SW1 set to BYP position: The sequence of events
a. The SW1 is set to BYP position on the drive enclosure/panel.
b. The step a above will put the drive in Bypass mode (See Figure 1).
c. Trigger start command to the drive like the start command to the drive in VFD mode.
d. The start command to the drive will trigger RO3, initiating the damper motion.
e. Once the damper position feedback is received, the bypass contactor will close.
3) Bypass mode during Emergency Faults, damper is manually operated.
In an unlikely event of failure of the VFD control board (MCU), the user can start the motor
in the bypass mode by manually moving the damper to the required position.
Sequence of events in this emergency bypass mode are as below:
a. User to manually position the damper to the required position to provide the
required position feedback to run the motor.
b. After the user verifies that the required position feedback is available, user turns
the SW1 to the BYP position.
c. SW1 in BYP position closes the bypass contactor starting the motor.
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(Please note that the damper position feedback will also close RO1 but in this mode
the bypass contactor pick-up is not dependeton RO1 status)

R1-K1
DPR-K1
R1
Com
Damper control using PowerXL DH1 Variable Frequency Drives Application Note
Effective March 2019
Figure 2: Standard schematic for Dh1 with damper control
DPR
24 V

Additional Help
In the US or Canada: please contact the Technical Resource Center at 1-877-ETN-CARE
or 1-877-326-2273 option 2, option 6.
All other supporting documentation is located on the Eaton web site at www.eaton.com/Drives
Eaton
1000 Eaton Boulevard
Cleveland, OH 44122 USA
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of their respective owners
Damper control using PowerXL DH1 Variable Frequency Drives
Application Note
Effective March 2019
© 2019Eaton
All Rights Reserved
Printed in USA
Publication No. AP040191EN
March 2019