Power-Off Behavior - Honeywell VB6 Series Installation Instructions Manual

IMPORTANT:
The zero (closed) position of the valve can be
achieved with control signal as shown in the
below table.
Valve closed command (45
degree actuator rotation)
Actuator Control Controller
Signal Setting Output
0-10 Vdc 5Vdc
2-10 Vdc 6 Vdc
10-0 Vdc 5Vdc
10-2 Vdc 6 Vdc
Floating/2-Position Run Mode
(Not recommended)
Using the MN7510A2001 actuator in floating /
2-position mode is not recommended with 6-way
valves. Both Sequence 1 and Sequence 2 are
closed at the actuator mid-stroke, 45 degree
actuator rotation. It must be possible to com-
mand the actuator to position itself in the mid-
stroke position, which is difficult to do with preci-
sion in floating mode, and impossible when float-
ing mode is used for 2-position control.
If it is desired to use the 6-way valve for simple
seasonal changeover service, it is best if three
distinct positions can be achieved:
1. Fully clockwise actuator rotation for
Sequence 2 to be fully open.
2. Fully counterclockwise actuator rotation for
Sequence 1 to be fully open.
3. Exactly mid-stroke, 45-degree actuator
rotation, for Sequence 1 and 2 both being
closed.
This scheme can only be achieved with the actu-
ator selector switch set to one of the four modu-
lating modes, using 0-10 Vdc, 2-10 Vdc, 10-0
Vdc, or 10-2 Vdc to achieve full clockwise, full
counterclockwise, and precisely mid-stroke actu-
ator positions. If desired, the actuator analog
feedback can be used to verify actual position.
If only step 1 and 2 above are desired, and there
is no need for step 3 to rotate the actuator to
exactly 45 degrees to turn both Sequence 1 and
2 completely off, the floating mode may be used
for 3-wire 2-position control.
9
VB6 SERIES 6-WAY CONTROL BALL VALVES AND ACTUATORS - INSTALLATION INSTRUCTIONS

Power-Off Behavior

If power is removed, the shaft adapter remains in
position.
Service/Off Mode
If the function selection switch is set to the "Ser-
vice/Off" position, then all rotary movement is
canceled, and all control signals are ignored,
allowing the actuator to be manually operated
safely. Press and hold the De-clutch button and
use the handle to operate the actuator to
Sequence 1, 2, or, Off positions.
Overriding
The MN7510A2001 can be overridden to the
50% position by applying a 24 V signal to termi-
nal 4 (see Figure 13.) With 24 V signal applied the
actuator will ignore the control signal at terminal
3 and instead drive to the 50% position closing
both Sequence 1 and Sequence 2.
Feedback
If correspondingly wired via terminal 5 (see Fig-
ure 13 to Figure 15), the actuator provides a
feedback signal proportional to the actual posi-
tion of the shaft adapter.
Printed in USA 31-00380M-02