Orion System Zoning - Manual (Page 23)

Orion Systems 23
Zoning Design Guide
Auxiliary Heat Control Options
The Orion Zoning system offers the user a variety of
methods to deal with zone heating requirements. In
order to control zone heat, an optional Relay Expansion
Board is required. When deciding how to handle zone
heating requirements the user should consider the
following:
•
Does the rooftop unit have heat?
•
Are you using fan-powered boxes with reheat?
•
Is auxiliary heat, such as baseboard or radiant
ceiling panels being used?
If the zone has some type of heat, the user must consider
how the heat is to be used. The following are things
that should be considered when configuring the
auxiliary heat.
Using the zone heat as a first stage where it will become
active before a heating demand is created at the rooftop
unit. This mode is useful if you expect to have both
heating and cooling demands at the same time. The
zone will use it’s own heat and allow the rooftop unit
to continue to provide cooling for other zones. This
mode is also useful if the roof top unit does not have
any heating capabilities.
Using the zone heat only as a second stage, where it
will be activated only if the roof top unit cannot
maintain the space temperature, such as during very
cold weather? In this mode of operation the rooftop
will examine the heating and cooling demands and try
to satisfy all of the zones by switching between heating
and cooling as required. The zone heat will only be
activated if the zone temperature falls below a fixed
limit from the setpoint.
The zone heat is locked out if the rooftop unit is
supplying hot air. Many times it is desirable to use the
rooftop heating whenever possible and only use zone
heat when the rooftop unit is in cooling. This mode of
operation will lockout zone heat if the rooftop is
delivering heated air that is 10° above the heating
setpoint.
Zone Controller Expansion Boards
The following describes the operation of each of the
relays on the optional OE 321 Relay Output Expansion
Board and the optional OE322 Analog/Relay Output
Expansion Board. Both boards have 3 usable relay
outputs. The OE322 Analog/Relay Output Board in
addition, has a 0-10VDC analog output for control of a
modulating hot water valve.
Output #1 - Relay Output - Series or Parallel Fan
If the VAV/Zone controller is configured for Series Fan
terminal, this output will be energized anytime the main
HVAC unit is on. If the controller has been configured
for Parallel Fan operation, this output will energize
when the zone temperature drops below the heating
setpoint. It deactivates when the temperature rises 0.5
°
above the heating setpoint. This output can also be
configured to activate when the damper closes to a
minimum position or a minimum CFM for pressure
independent zones.
Output #2 - Relay Output - Heat
This heat output can activate anytime the zone
temperature drops below the heating setpoint. It
deactivates when the temperature rises 0.5
°F above the
heating setpoint. In the unoccupied mode, the
unoccupied heating setpoint, with adjustable deadband
values, is used. This allows the zone to maintain a lower
heating setpoint at night than it does during the daytime.
This heat output is not allowed to activate if the air
being supplied by the air handling unit is 10
° or more
above the heating setpoint. This output is intended to
allow zone reheat while the Polling Device is satisfying
cooling demands in other zones. This output is also
intended to allow zone heating to augment the normal
heating mode and to allow a zone an attempt to satisfy
its own heating needs before creating a heating demand
at the Polling Device.
Output #3 - Relay Output - Heat
In the occupied mode, this heat output will activate
anytime the zone temperature is 1.0
°F below the heating
setpoint. It deactivates when the temperature rises to
0.5
°F below the heating setpoint. In the unoccupied
mode, the unoccupied heating setpoint, with the same
deadband values mentioned above, is used. This allows
the zone to maintain a lower heating setpoint at night
than it does during the daytime.
Output #4 - OE321 Relay Output Board (Not Used)
Output #4 - OE322 Analog/Relay Output Board
(Modulating Hot Water Heat)
This relay output is not used on the OE 321 Relay
Output Expansion Board. On the OE 322 Analog/Relay
Output Board, it supplies a 0-10VDC or 2-10VDC
signal to control a modulating hot water valve. The
output voltage starts to increase from minimum as the
space temperature drops to
0.5
°F above the heating
setpoint and will be at the full 10 volts when the space
temperature is 1.5
°F below the heating setpoint.