Product Overview

© Danfoss | DCS | 2019.04
Data sheet | Superheat controller type EKE 1A, EKE 1B, EKE 1C
DKRCC.PD.RS0.A4.02 | 74
Danfoss 80G248.10
Actual opening degree
Overdrive
enable
Overdrive
No overdrive
Opening degree is above
overdrive enable level so
overdriving is enabled
Time
The opening degree needs to be above this value, before the overdrive will become enabled. When the
overdrive is enabled the valve will overdrive once it is closed to 0%. The amount of extra steps is dened
by the parameter [I072 - Overdrive] and is scaled as a percentage of the full opening. The parameter
[I073- Overdrive Enable OD] denes how much the valve must have been open before overdrive is done
at next close position and is scaled as a percentage of full opening.
To compensate for lost steps, the valve will be overdriven when it closes to 0%. i.e. it will close with
extra steps to make sure that it is fully closed. This may however lead to increased wear on the valve if it
occurs frequently. To prevent this, the overdrive enable can be set to a higher value.
Please note that if the opening degree never goes above the overdrive enable level, overdriving may
never be enabled, possibly leading to accumulated lost steps. Every time an overdrive has been
performed, overdriving will be disabled until the opening degree again is above the overdrive enable
level.
To limit how frequent overdrive can performed the parameter [I074 - Overdrive block time] denes
the minimum time between 2 overdrive actions. The default value is 10 minutes.
Overdrive block time
Initial closing
The driver will perform the initial closing after
• Power up
• When the total number of steps changes
• When the drive pattern changes (full/half step as nal position)
The driver does not have to perform the initial closing at power up
when it knows that the valve is closed e.g. after power failure and
successfully emergency close.
Operation:
The valve is driven the total number of steps + overdrive in close
direction.
Danfoss 80G8350.10
Actual opening degree
Overdrive
enable
No overdrive
No overdrive
Overdrive
Overdrive
Overdrive block time
Danfoss 80G8351.10
Full stroke
closing
Overdrive
Actual opening degree
Appendix 7
Overdrive enable