Messana mZone, Руководство по установке

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Power pick optimization
note 1
Time
Power pick is reduced by 40%
Power
7.2W x N/2
6W x N
1W x N/2
Start 2 minutes
Legend

Staggered activation with two groups of actuators each

Normal activation
N Is the total number of thermal actuators
6W x N/2
Power pick (6W x N)
2W x N/2
10
The Messana thermal actuators are based on a PTC resistor-heated elastic element and a return compression
spring. When the elastic element is heated by applying the 24V voltage to the PTC resistor, it expands and moves an
integrated plunger to open the valve. When the PTC resistor stop being energized, the elastic element shrinks and
the return compression spring moves the plunge back and close the valve.
During the activation of the actuator there is an initial phase of about 2 minutes where more heat is necessary to
expand the elastic element. During this initial phase the current spikes up to 6 times the nominal current needed to
hold the actuator activated. This initial high load (6 Watts per actuator) limits the number of thermal actuators that
can be activated simultaneously based on the total available power supply. Once the actuator is open, the elastic
element needs to be maintained hot and this requires only 1 Watt per actuator (nominal power).
When sizing the power supply of zoning module, in order to satisfy the initial rush current needed to open
simultaneously all the actuators, it requires 6W x N (total number of actuators). With the intent of optimizing
the maximum number of actuators that can be driven by one mZone module, Messana has developed a new
technology that staggers the activation of actuators and avoid the initial load pick. It is a group delay mechanism
that prevents to turn on multiple actuators at the same time to prevent power surge. The actuators attached to the
mZone are divided in two groups of N/2 actuators each.
The staggered activation logic activates the first group of actuators (group #1) and wait until they complete the
initial opening phase (about 2 minutes). Once the first group of actuators is partially open, and the power has
dropped close to its nominal value (1W x N/2), the logic starts the activation of the second group of actuators
(group #2).
With an overall delay of 2 minutes, the staggered activation logic can operate two distinct groups of actuators and
reduce the power pick by about 40%. This allows to increase the total number of thermal actuators by 66%
This is particularly useful when controlling radiant floors where typically there are several loops attached to the
same zone.
Staggered activation of the thermal actuators
Notes 1. Staggered activation with 2 groups of thermal actuators. Group #1 is activated fist and Group # 2 is activated with 2 minutes of
delay to minimize the power pick. It turns out that the power pick is reduced by 40%. This allows the mZone controller to drive up
to 66% more thermal actuators.