Reverse Acting Relay - Emerson Fisher Fieldvue DVC6030f Instruction Manual

ADJUSTMENT DISC
Figure 6-2. Location of Relay Adjustment
(Shroud Removed for Clarity)
Relay Adjust
(TB > Calibrate > Relay Adjust)
Note
Relay adjustment for single acting
relays is not normally required.
However, it is recommended that you
check the relay adjustment for double
acting relays in new installations
before proceeding with travel
calibration.
Single-Acting Actuators
For single-acting direct digital valve controllers, make
sure the adjustment disc is against the beam, as
shown in figure 6-2. For single-acting reverse digital
valve controllers, the relay is adjusted at the factory,
no further adjustment is necessary.
March 2006
FOR SINGLE-ACTING DIRECT RELAYS:
ROTATE ADJUSTMENT DISC IN THIS
DIRECTION UNTIL IT CONTACTS THE
BEAM
FOR DOUBLE-ACTING RELAYS:
ROTATE ADJUSTMENT DISC IN
THIS DIRECTION TO DECREASE
OUTPUT PRESSURE
FOR DOUBLE-ACTING RELAYS:
ROTATE ADJUSTMENT DISC IN
THIS DIRECTION TO INCREASE
OUTPUT PRESSURE
Double-Acting Actuators
Note
Converting a Type A relay from
single-acting to double-acting requires
several full turns of the adjustment
disc in the + direction (increasing
output pressure). The first few turns
will not produce any change in output,
however as you approach the correct
position, both Output A and Output B
will begin to change rapidly with very
little additional disc rotation. Watch
the output gauges to detect nearing
the correct position and avoid rotating
the adjustment disc too far. If using
the Field Communicator and no
gauges are available, listen for an
audible change in relay bleed to detect
nearing the correct adjustment disc
position.
For double-acting actuators, the valve must be near
mid-travel to properly adjust the relay. The Field
Communicator will automatically position the valve
when Relay Adjust is selected.
Rotate the adjustment disc, shown in figure 6-2, until
the output pressure displayed on the Field
Communicator is between 50 and 70% of supply
pressure. This adjustment is very sensitive. Be sure to
allow the pressure reading to stabilize before making
another adjustment (stabilization may take up to 30
seconds or more for large actuators).
If the the low bleed relay option has been ordered
stabilization may take approximately two minutes
longer than the standard relay.

Reverse Acting Relay

The reverse acting relay is designated by "Relay B" on
a label affixed to the relay. In single acting mode,
pneumatic reverse action can only be achieved with
"Relay B" and cannot be achieved through adjustment
of the standard direct acting "Relay A". Normally
"Relay B" is calibrated at the factory and requires no
further adjustment. However, if you feel that the relay
needs adjustment, perform the following steps.
1. Verify Configuration
A reverse acting DVC6000f Series digital valve
controller requires different configuration settings for
Calibration
6
6-5