Thermic actuators TWA-Z

Data sheet
Thermic actuators
TWA-Z
Description
Danfoss thermic actuator TWA-Z is used with
Danfoss valves type VZL or with automatically
balanced combination valves type AB-QM.
The actuator can be controlled with a room
thermostat. These provide a cost effective
solution for the control of hot and /or chilled
water for fan coil units, small reheaters and
recoolers in temperature control systems.
Main data:
• 24 and 230 Vac/dc supply
• Visual position indicator
• Normally closed (NC) and normally open (NO)
version.
Ordering
Type
Power supply
Code No.
24 V~
082F1220
TWA-Z NO
Technical data
SIBC
TWA-Z NC
24V~
082F1222
TWA-Z NO
230 V~
082F1224
TWA-Z NC
230 V~
082F1226
Power supply
24 V (Class II (SELV); 230 V (3A pre-fuse)
Power consumption
2W
Frequency
50 Hz / 60 Hz
Close of force
90 N
Max. stroke
2.8 mm
Full stroke time
approximately 3 minutes
Ambient temperature
2 ... 60 °C
Protection code
IP 41
Actuator material
PBT
Cable length
1200 mm
Weight
0.15 kg
VD.JC.J1.02 © Danfoss 11/2004
1
Data sheet
Thermic actuators TWA-Z
Operation
The thermic actuator TWA-Z rely on the thermal
expansion principle to move the valve stem, and
on its contraction to move it back again.
Normally open
The actuator is equipped with a visual position
indicator to show the open or closed position of
the valve.
The actuator is made for either 24 V (SELV) or 230 V
supply in both normally closed (NC) or normally
open (NO) versions (valve positions with no
supply voltage to the actuator).
The VZL valve is normally closed, i.e. the valve
stem is driven up, fully closing the A to AB path,
under its internal spring. For the four port version
only, the B to AB path is fully open.
The actuator (NO version) will thus fit on the
valve with the valve stem up in the unenergised
state, and will drive the valve stem down when
it is energised, opening the A to AB path (and
closing the B to AB path for the four port version
only).
The TWA-Z NC, normally closed actuator, has an
internal spring and is fitted with a split ring to
hold the spring closed in its off-the-shelf state.
The split ring allows the actuator to be fitted to
the valve; once fitted, the split ring is removed,
and the actuator spring drives the valve stem
down and closes the AB-QM valve / openes the
VZL valve. When the actuator is energised, the
wax pellet pushes up against the actuator spring
and drives the valve open / close.
Valve Position Indication
The valve position is indicated by position of the
the inner black cover relative to the white outer
sleeve of the actuator. When the inner black cover
projects above the white outer sleeve, the valve
stem is up, and as the actuator moves the stem
down, the inner black cover moves down below
the level of the white outer sleeve.
Disposal
The actuator must be dismantled and the
elements sorted into various material groups
before disposal.
2
VD.JC.J1.02 © Danfoss 11/2004
TWA-Z + AB-QM
Normally closed
TWA-Z + VZL
NC version
valve stem up
valve stem down
SIBC
Data sheet
Thermic actuators TWA-Z
Installation
Mechanical
The actuator should be mounted with the valve
stem either horizontal or pointing upwards.
The actuator should be placed over the top of
the VZL valve, fixed to the valve body by means
of a mounting ring which requires no tools for
mounting. The ring should be tightened by hand.
Dimensions
Actuator - valves
combinations
TWA-Z + AB-QM
SIBC
VD.JC.J1.02 © Danfoss 11/2004
TWA-Z + VZL
3
Data sheet
Thermic actuators TWA-Z
4
VD.JC.J1.02 © Danfoss 11/2004
SIBC
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