Brochure

Tunstall Corporation
118 Exchange Street • Chicopee, MA 01013
© July 2014
We reserve the right to alter designs, specifications and information without notice.
Phone [phone] · Fax [phone]
www.tunstall-inc.com • www.maconcontrols.com
Bulletin-ZMC-DDC-0714
Electric Operators
ELECTRIC ZONE VALVE ACTUATOR
ZMC - DDC Series
1
Macon ZMC - DDC
The Macon Model ZMC-DDC Proportional is a
thermoelectric actuator for the discrete control of
heating and cooling systems in direct proportion
to the applied control voltage. The control of the
actuators is performed by a 0-10 V DC signal via
a central DDC system or by a room thermostat.
Principal area of application is the building man-
agement systems range.
1) Features
• Simple plug-in installation
• Travel path variants 4.0 mm / 5.0 mm (further
variants on request)
• “normally closed” (NC)
• Power consumption of only 1 watt
• Control by a 0-10 V DC signal
• 360° installation position
• Short response times, resulting in improved
control response
• Closing point verification and possible adapta-
tion during operation
• All-round function display
• Complete compatibility to the valve adapter
system
• Noiseless and maintenance-free
• High functional safety and long expected ser-
vice life
• Patented 100% protection in case of leaky
valves
• “First open” function
• Adaptation check on the valve
• Plug-in connecting cable
• Alignment aid on the valve
• Compact size, small dimensions
2) Function
The actuator mechanism of the Macon ZMC-DDC uses a PTC resistor-heated elastic element and a compression spring. The
elastic element is heated by applying the operating voltage and moves the integrated plunger. The force generated by this
movement is transferred to the plunger, thus opening or closing the valve.
2.1 Version NC: Normally Closed (valve closed)
After switching on the operating voltage, the first-open function is unlocked. Directly after that, the actuator automatically
detects the valve closing point and switches to regular operation. This process guarantees an optimum adaptation of the actua-
tor to the valve. If a control voltage is applied after the closing point detection, the actuator opens the valve evenly with the
plunger movement after the dead time has elapsed. An internal wear-free position detection controls the temperature required
for the maximum stroke (minus over-elevation) and consequently the energy intake of the elastic element. No excess energy
is stored inside the elastic element. If the control voltage is reduced, the electronic control system immediately adapts the heat
input to the elastic element. In the range of 0 – 0.5 V (depending on the model) the actuator remains in a quiescent state in
order to ignore ripple voltage occurring in long cables (rpm). The closing force of the compression spring is matched to the
closing force of commercially available valves and keeps the valve closed when de-energized.