Polyaire Zonemaster Variable Air Volume, Техническое руководство и руководство пользователя

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3) Press button once again, the LCD
screen will display the ‘L_Limit’.
4) Press or button to change the
low limit to the desired value. The adjustable
range of the low limit is from 0°C to 15°C.
If the customer does not want the safety
function, the safety H-limit and L-limit
MUST be disabled by pressing button
during the setup.
Spill or Bypass Modes
A ‘Spill’ or “Bypass” function is designed to relieve pressure in the duct if
too many zones have been turned off.
Spill Mode
The VAV system has an inbuilt “Spill” system that will automatically open
vents if too many have inadvertently been closed. The preset factory
default is 30% of the total number of zones. The Preset Factory default
can be varied but we recommend 30% as the lowest safe value to protect
the duct. In Spill mode the zones with the lowest addresses in the system
are automatically opened if the total number of open zones is less than the
assigned spill setpoint. (IE: If the system has 10 zones numbered 1- 10
and all have been closed the VAV will automatically open zones 1,2, 3 to
relieve the pressure. The only way to close these “spill” zones is to make
sure at least 3 other zones are open.
Bypass Mode
The alternative way to relieve pressure in the duct is to install a duct from
the A/C outlet via a motorized damper to the return air duct. This system
should only be used where the spill function is considered unsatisfactory.
In Bypass mode, a specific damper is used to return the air directly to the
return air duct if the total number of zones open is less than the setpoint.
The bypass damper is controlled by a specific damper controller with its
own unique address.
Note: Ensure that the Air Con Unit Return Air Sensor is positioned in the
return air duct between the Bypass duct and the unit so that it can register
the air from the bypass duct.
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