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50-60 Hanover Road, Florham Park, New Jersey 07932 www.ascovalve.com
e
MCMXCIX All Rights Reserved.
Printed in U.S.A.
Installation & Maintenance Instructions
Form No.V8700R1
HYDRAMOTOR
r
PUSH-TYPE LINEAR ACTUATORS
AH2D
HYDRAMOTOR
r
ACTUATOR
SERIES
WARNING
To prevent the possibility of death, serious injury or
property damage, the Hydramotor
r
Actuator must be
installed and serviced only by a qualified service
technician avoiding the following hazards:
S
Electrical hazard. Turn off all electrical power to
Hydramotor
r
Actuator. More than one circuit may
exist.
S
Pressure hazard. Depressurize valve and vent
hazardous or combustible fluid to a safe area before
inspection or removing the actuator or valve from
service.
S
Explosion,Ă fire or toxic Ăgas Ăhazards. Extinguish all
open flames and avoid any type of sparking or
ignition during leakage testing.
NOTICE: See separate valve installation and maintenance
instructions for information on: Operation, Positioning,
Mounting, Piping, Strainer or Filter Requirements, Flow
Controls, Preventive Maintenance, and Cause of Improper
Operation.
DESCRIPTION
AH2D Hydramotors
r
are self-contained linear, push-type
actuators which extend when powered and retract by spring
force upon power interruption.
The AH actuator is typically used for control of gas-fired
heating equipment, commonly to open and close a valve or
both a valve and damper. AH2D actuators position V710
Series gas valve assemblies.
OPERATION
Application of electrical power simultaneously drives an
electric pump and closes a normally-open dump valve,
resulting in up to 250 pounds of force on the actuator stem. This
extends the actuator stem and attached valve poppet, to open
the valve and/or damper.
Upon reaching the fully extended position, a travel limit switch
interrupts power to the electric motor while maintaining power
to the dump valve, thus stabilizing hydraulic pressure to hold
shaft position. Position indicators on both sides of the actuator
show the actual position of the valve stem.
Upon power interruption, the dump valve opens releasing
hydraulic pressure, allowing the return spring to retract the
stem and close the valve fully. Closing time is one second or
less.
OPTIONAL FEATURES
S
Damper Shaft & Arm
Shaft with all components to mount
damper arm on either side of actuator. Available with or
without return spring.
S
Auxiliary Switch
One or two integral SPDT switches,
field adjustable to actuate at any position of stroke.
S
Overtravel Proof-of-Closure Switch
A single factory set
non-field adjustable SPDT switch to be used in conjunction
with V710 Series Gas Valves with overtravel seal (V22 or
V25 suffix in catalog number).
Figure 1. AH2D Actuator (shown mounted
on V710 series gas valve)
ACTUATOR
ASSEMBLY
COVER
COVER
SCREW
CONDUIT
KNOCKOUT
STEM POSITION
INDICATOR
DAMPER
ARM
DOWNSTREAM
PRESSURE TAP
UPSTREAM
PRESSURE TAP
(OPTIONAL)
AH2D
ELECTRICAL
VALVE
ASSEMBLY
(2)
NAMEPLATE/
Figure 2. Cutaway schematic
(de-energized position)
OIL FILL PLUG
MOUNTING
PISTON
ACTUATOR STEM
HYDRAULIC
FLUID LEVEL
INTERNAL
RESERVOIR
SPRING
SET SCREW (2)
TRAVEL LIMIT
SWITCH
HOLE IS SHOWN 90
_
OUT OF
TRUE POSITION
