Automax actuator and H-4000 positioner
Where can I find technical reference material for an Automax model R312PSR80 actuator?
It
is being used here with a butterfly valve on a 24" line. The
positioner is an Automax H-4000 with 4-20 I/P and 3-15psi output.
Specifically,
I need maintenance data to troubleshoot, test and prove the operation
of the 90 degree span butterfly. The actuator R312PSR80 has 2 air
chambers.
I need specifics on the ports, connections and operation of this device.
H4000 positioner is obsolete but it is calibrated much as any
force-balance positioner. Zero-adjustment is a thumbwheel at the bottom
of the spring. Span adjustment is at the top of the spring and changes
the stiffness by changing the number of active coils,but that does
interact with the zero setting. Once the span adjustment is set it does
not drift, and the only adjustment you should ever have to touch again
should be the zero if you disturb the cam or move the positioner to a
different valve. Current replacement for the H4000 is the APEX type
5100 positioner, which has noninteractive zero and span.
To
set the zero, apply 4 ma to the contacts and watch the output
gage. Apply very small movements to the zero screw until the valve
begins to move. Back off on the screw until the valve closes and the
Output Pressure needle just falls to zero. Best to make very small
movements and wait to see what happens for 15-20 seconds. Once the unit
is zeroed, apply 18 ma, then 19, then 20, and the valve should stroke to
full travel at 20 ma. Since the span and zero are interactive, if you
find it necessary to set the span, you will need to reset the zero. You
can chase yourself for hours unless you set the span first and then dial
in the zero.
To set the span, first loosen the lock screw at the
top of the spring so the spring can be rotated. At zero signal, adjust
the span spring a tiny amount. apply signal gently and record the
signal at which the valve starts to move. Do not touch the zero
adjustment. Keep increasing signal and record the signal at which the
valve becomes fully open. When you have the span correctly set the
difference should be 16 ma. If you don't have a 16ma span, Tweak the
adjustment and repeat the span measurement until you get 16ma. THEN set
the signal at 4 ma and adjust the zero adjustment until the output gage
goes to zero. Make small adjustments. You can overshoot and miss the
correct zero setting easily especially with such a large actuator. It
takes a while to respond to tiny incremental changes.
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