Flowserve L120-85 Actuator - Manual (Page 16)

Figure 8: Limit Switch Rotor development
NOTES
1. Contact Open
2. Contact Closed
3. All limit switch trip points
are fully adjustable.
.
BY-PASS CIR.
IND LIGHT
OPEN LIMIT
BY-PASS CIR
IND LIGHT
CLOSE LIMIT
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
FULLY
OPEN A B FULLY
CLOSED
VALVE SHOWN IN FULL OPEN POSITION
INDICATION
INDICATION
LIMIT SWITCH CONTA CT DEVELOPMENT
VALVE POSITION
ROTOR
OPEN
CLOSE
INT.1
INT.2
FUNCTION
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
CONT
AC
T
THE LIMIT SWITCH IS NOT PRESET at the Limitorque factory, and
must be set after mounting on the valve or other associated equip-
ment. If your L120-85 actuator has been shipped already installed
on your equipment, your actuator should have the Limit Switch set
for your application. If your actuator is not already installed on your
equipment or needs resetting, use the following instructions to make
the appropriate settings.
The following instructions for setting the Limit Switches are based
on the typical orientation for most actuator applications (CCW
to OPEN and CW to CLOSE). Consult the applicable wiring
diagra located in the actuator Electrical Compartment for your spe-
cific Limit Switch development.
4.5.1 Basic Theory of Operation
The Limit Switch (piece 305) is driven directly by the Worm Shaft
through the Limit Switch Pinion. Therefore, the Limit Switch is
directly connected to the output of the actuator. Once the Limit
Switch is properly set, it measures the position of the valve, or other
equipment, in the ELECTRIC or MANUAL operating modes.
The OPEN Rotor consists of contacts 1 through 4. These switches
are set to change state at the full OPEN position. The switch func-
tions are as follows:
Contact 1 is the CLOSED Torque Switch bypass circuit. It’s purpose
is to allow the electric actuator to apply its full torque to unseat a
backseated valve. When a valve is manually backseated to prevent
packing leakage, it may stick momentarily when first operated. To
prevent the CLOSE Torque Switch from stopping the actuator dur-
ing unseating, this momentary bypass is applied. The OPEN Rotor
actuates at the full OPEN position causing contact 1 to open as soon
as the valve moves in the close direction, thus returning the Torque
Switch function to the control circuit.
Contact 2 is normally used for a Remote Valve Position Indication
Lamp. As shown in Figure 8, the lamp will be turned ON when the
valve reaches the full OPEN position.
Contact 3 is for the Local Position Indication Lamp; included as part
of the actuator assembly when required. This switch turns the green
lamp/LED OFF in the full OPEN position, leaving the red lamp/LED
energized and indicating that the valve is OPEN.
Contact 4 is the OPEN Limit Switch which opens the control circuit
to de-energize the Motor at full OPEN position.
The CLOSE Rotor consists of contacts 5 through 8. This Rotor is set
to change state at the full CLOSE position. Switch functions are as
follows:
Contact 5 is the OPEN Torque Switch bypass. After the valve
has been tightly closed, it may stick when it is first opened which
would cause the Torque Switch Contacts to break. To momentarily
overcome this sticking, the OPEN Torque Switch is bypassed. This
OPEN Torque Switch bypass is part of the closed valve position
rotor so that as soon as the valve moves in the OPEN direction, the
bypass contact opens and the OPEN Torque Switch control function
is returned.
Contact 6 is normally used for a Remote Valve Position Indication
Lamp. As shown in Figure 8, the lamp will be turned ON when the
valve reaches the full CLOSE position.
Contact 7 is for the Local Position Indication Lamp; included as part
of the actuator assembly when required. This switch turns the red
lamp/LED OFF in the full CLOSE position, leaving the green lamp/LED
energized and indicating the valve is in the full CLOSE position.
Contact 8 is the CLOSE Limit Switch that opens the control circuit to
de-energize the Motor at full CLOSE position.
c WARNING: Do not manually operate actuator with devices
other than installed Handwheel and Declutch Lever. Using
additive force devices (cheater bars, wheel wrenches,
pipe wrenches or other devices of this nature) on the
actuator Handwheel or Declutch Lever may cause serious
personal injury and/or damage to the actuator or valve.
c WARNING: Hazardous Voltage. Make sure all power is
OFF before opening the Electrical Compartment Cover or
making the following settings.
Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-00 – 11/05
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