Install Instructions
The Variable Speed Delta T 00
®
Cartridge Circulator (00-VDT) is a microprocessor-based pump which automatically adjusts its perfor-
mance to deliver the optimal heat transfer based on the actual operation of the system. The 00-VDT regulates the temperature to provide
a fixed temperature difference (ΔT) of between 5 - 50°F between two field installed sensors.
Variable Speed Differential Temperature Control
Variable speed pumping to maintain a set differential temperature (delta T or ΔT) between two sensors allows for automatic adjustment of
the pump’s performance to match the load of the system or zone, eliminate velocity noise in zone valve systems and conserve energy.
Since delta T is directly related to flow rate, the pump’s speed continually adjusts to the required BTU per hour. In almost all applications
the design of the system was based on being able to maintain a certain delta T and figured by using the universal hydronics equation of
BTU/hr = GPM x 500 x ΔT. Given that, any time there is a change to the heat load (i.e. warmer day or greater heat loss from a structure)
then the GPM should change to match the required BTU/hr. This is achieved when the variable speed 00-VDT Circulators automatically
and continually adjust their GPM output (by varying speed) to match the required BTU/hr output of the system, no matter the changes
in heat load, while always maintaining the designed delta T between a supply and return sensor.
Applications
Instruction Sheet
00
®
Variable Speed Delta T (00-VDT)
102-359
SUPERSEDES: May 1, 2010 EFFECTIVE: October 1, 2010
Plant ID# 001-3927
DIP 5 = Off
DIP 4 = Off
DIP 3 = On
DIP 2 = Off or On
DIP 1 = On
Delta T Across a Series Loop System Using Zone Valves
"00"-VDT
Supply
Sensor
M
M
Return
Sensor
M
The 00-VDT Variable Speed Circulator adjusts its speed to maintain the differential temperature (based on the RANGE dial setting) between the
supply sensor and the return sensor whenever a heat demand is present. This will increase overall comfort and sharply reduce boiler short-cycling.
The 00-VDT will also control velocity noise issues in the system, eliminatin
g
the need for a pressure differential bypass valve.
DIP 5 = Off
DIP 4 = Off
DIP 3 = On
DIP 2 = Off or On
DIP 1 = On
Delta T Across Multi-Zone Radiant Manifolds with Loop Actuators
iSeries-R
B
C
A
B
C
A
“00”-VDT
Supply
Sensor
Return
Sensor
M M M M
Outdoor
Sensor
Boiler
Sensor
The 00-VDT Variable Speed Circulator adjusts its speed to maintain the differential temperature (based on the RANGE dial setting) between the
supply sensor and the return sensor whenever a heat demand is present. The 00-VDT will also eliminate velocity noise by slowing the actual flow
rate through the zone to the minimum required to deliver proper heat. If other zones on the manifold open, the 00-VDT will increase its speed to
deliver the required BTU’s, while at the same time maintaining the designed for delta T across the radiant system.
See www.taco-hvac.com for additional applications for the 00-VDT circulators.
A Taco resource – saving product