To prevent a risk of injury due to electrical shock
and/or damage to device due to short-circuiting,
low-voltage and high-voltage lines must be kept
physically separate from one another. Further, to
prevent a risk of short-circuiting and damage to
your unit, do not reverse the polarity of the power
connection cables, and avoid ground loops (i.e.,
avoid connecting one field device to several
Before wiring the controller, determine the input
and output device requirements for each controller
used in the system. Select input and output
devices compatible with the controller and the
application. Consider the operating range, wiring
requirements, and the environment conditions
when selecting input/output devices. The Actuator,
COVA must be used in combination with the
controller WEB-V423B24N. See Product Data 31-
00361 for individual part model numbers.
Determine the location of controllers, sensors,
actuators and other input/output devices and
create wiring diagrams for illustrations of typical
controller wiring for various configurations. Refer
Fig. 18 on pg.16 for example wiring.
The application engineer must review the control
job requirements. This includes the sequences of
operation for the controller, and for the system as a
whole. Usually, there are variables that must be
passed between the controller and other Spyder
BACnet controllers that are required for optimum
system wide operation. Typical examples are the
TOD, Occ/Unocc signal, the outdoor air
temperature, the demand limit control signal, and
the smoke control mode signal.
It is important to understand these
interrelationships early in the job engineering
process, to ensure proper implementation when
configuring the controllers.
All wiring must comply with applicable
electrical codes and ordinances. Refer to
job or manufacturers' drawings for details.
Local wiring guidelines (for example, IEC
364-6-61 or VDE 0100) may take
precedence over recommendations
provided in these installation instructions.
To comply with CE requirements, devices
having a voltage of 50-1000 VAC or 75-
1500 VDC but lacking a supply cord, plug,
COMPACT VAV CONTROLLER WEB-VA423B24N – INSTALLATION INSTRUCTIONS
or other means for disconnecting from
the power supply must have the means of
disconnection incorporated in the fixed
wiring. This type of disconnection must
have a contact separation of at least 3
mm at all poles.
All wiring must comply with applicable electrical
codes and ordinances, or as specified on
installation wiring diagrams. Controller wiring is
terminated to the screw terminal blocks located on
For multiple controllers operating from a
single transformer, the same side of the
transformer secondary must be
connected to the same power input
terminal in each controller. Controller
configurations will not necessarily be
limited to three devices, but the total
power draw, including accessories,
cannot exceed 100 VA when powered by
the same transformer (U.S. only).
All loads on the controller must be
powered by the same transformer that
powers the controller itself. A controller
can use separate transformers for
controller power and output power.
The 24 VAC power from an energy limited Class II
power source must be provided to the controller. To
conform to Class II restrictions (U.S. only), the
transformer must not be larger than 100 VA. Fig.
12 depicts a single controller using one
Power must be off prior to connecting to or
removing connections from the 24 VAC
power (24 V~/24 V0), and 20 VDC power
(20 VDC) terminals.
Use the heaviest gauge wire available, up
to 18 AWG (0.8 mm
22 AWG (0.3 mm
More than one controller can be powered by a
single transformer. Fig. 13 shows power wiring
details for multiple controllers.
), with a minimum of
), for all power wiring.