Taco Viridian 15, Instruction Sheet, Page: 3 / 12

3
The pump has built-in over current fuse protection, temperature
protection and basic overvoltage protection. It does not require
additional overload protection devices unless required by local
electrical codes. Power supply cabling should be capable of carry-
ing rated power and be properly fused. Ground lead connection is
essential for safety and should be connected first. Grounding is
only meant for pump safety. System piping should be grounded
separately. A ferrite core is supplied in a separate bag. Electronic
cabling and wires, by virtue of their length-to-width ratios, are per-
fect natural antennas. The ground, line and neutral power supply
wires should go through the ferrite core to help reduce unwanted
high-frequency interfering signals. The pump should not be oper-
ated without the electrical cover securely attached.
B.' RelaG Connections:
The pump is supplied with normally open, normally closed and
common relay connections. See Section 9.2
Electrical Data
for
specifications. These can be used to activate or deactivate a pri-
mary or secondary pump or alarm contact, actuate a damper for
combustion air or switch another piece of equipment. Factory
default is activation of relay on fault. Additional relay “triggers” are
standby, I2 activation and run digital input commands.
B.B Digital Inputs:
The pump can be switched between standby mode or maximum
power via the digital inputs.
B.B.1 Pump Ezternal Control Hiring Diagrams:
The following diagrams are examples of external control wiring to
digital inputs I1 and I2.
B.B.- Ezternal Control Settings:
On/Off/Standby/Max speed external control variances and subse-
quent effects are listed in the chart below. Refer to Section 6.5
Pump Settings
to modify digital input and relay settings from fac-
tory defaults.
B.4 Constant -B olt DC PoWer SupplG:
There is a constant, unswitched 24Vdc/100mA output power supply
across terminals 24V/0V. This power is interrupted only if the main
power supply to the Viridian is turned off.
4. REbULATION MODES:
Pump defaults to provide 23 feet (7m) of head with variable differ-
ential pressure (
∆
p-v) regulation. If the factory settings are not
suitable they can be modified over an Ethernet connector or a web
interface. Various regulation parameters (constant head, supply
power, rpm limit) can adjust the head and flow characteristics until
the pump achieves desired response to suit the application.
4.1 Constant Pressure Control )
∆
pYc0:
Electronic regulation can provide
constant head by modifying power
input and is set with the
Limit
head (Hmax)
setting. The duty
point of the pump will move left
and right along a constant-pres-
sure curve based upon the water
demand in the system. The pump
head (pressure) is kept constant,
irrespective of the water demand.
Hmax proportional to Q
needs to
be set to 0% (see Section 6
Connection to a Network -
Pump Setup
)
.
Selecting the constant pressure regulation is beneficial when the
Viridian is installed in a system where there is a much lower resis-
tance (friction loss) in the main distribution loop compared to the
resistance in the transfer part of the system (i.e. baseboard radia-
tion, radiant floors, terminal units). For example, this characteristic
of generally lower head loss can be found in converted gravity sys-
tems, systems operating with large temperature spreads or where
the pump is moving the total volume of flow through the boiler and
distribution lines.
4.- ariaVle Differential
Pressure Control )
∆
pYv0
Y FactorG Default Setting:
Additional energy savings and
noise reduction is achieved with
proportional head regulation that
also compensates for changes in
system friction losses during peri-
ods of changing flow rates. In this
mode the pump head changes
continuously as the demand for
water changes, reducing as the
water demand declines and
increasing as the water demand rises.
The
Hmax proportional to Q
setting provides a user adjustable
curve slope. An
Hmax proportional to Q
of 0% means that the
head does not exhibit any dependence to flow and should not
exhibit noticeable change until maximum power is reached. An
Hmax proportional to Q
set to 60% means that the pressure will
drop for 60% from set value when there is no flow. For example if
the head is set to 20', the pump will only provide 12' when the
valves are closed and the pump is dead headed (operating at zero
flow). The factory default is 23' at 50%. Note, a substantial per-
centage of glycol in the mixture can influence regulation.
Select the variable differential pressure control when the Viridian is
installed in a system where there is a much higher resistance (fric-
tion loss) in the main distribution loop compared to the resistance
in the transfer part of the system (i.e. baseboard radiation, radiant
floors, terminal units). For example, this characteristic of the prima-
ry circuit having a high pressure drop can be seen in systems using
modulating condensing boilers or heat exchanges, heavily throttled
branch shut-off valves, where the distribution lines are long or in
two pipe systems with thermostatic or zone valves.
FACTORw DEFAULT FUNCTION
I1 (IO1/0V)
Normally open or 2Vdc and less, pump runs normally.
Closing contact (or applying 8Vdc or above) sets the
pump to standby mode by disabling power to the motor
(eg: for Warm Weather Shut Down). Additional I1 input
signals are maximum power (speed) and no effect.
I2 (IO2/24V)
Closing I2 or 8Vdc and above (only when I1 is closed)
forces the pump to run at Max (eg: purge system of air
on start-up). Has no effect if I1 is open. Additional I2 input
signals are run and no function.
0 IO2 24 IO1
DC Source
IO1 “Open”
IO2 “Open”
IO2 “Closed”
IO1 “Closed”
Pump Control Using Switches or Other
“Dry” Contacts Such as a Relay
0 IO2 24 IO1
IO2
> 8 Vdc = “Closed”
< 8 Vdc = “Open”
DC Source
IO1
> 8 Vdc = “Open”
< 2 Vdc = “Closed”
Pump Control Using a DC Source Such as
From a BMS or Other Controlling
Voltage Source
Note: Maximum voltage on the IO terminals
is not to exceed 32 Vdc
H
H
set
Q
CONSTANT
PRESSURE
CONTROL
H
H
set
H
set
2
Q
PROPORTIONAL
PRESSURE
CONTROL