2.
APPLICATION AND DESIGN CONSIDERATIONS
a.
Air conditioning control systems require the air handling equipment be properly sized for
the application; otherwise, satisfactory temperature control may not be realized.
b.
Oversizing of HVAC equipment is not recommended. In most cases it is better to slightly
undersize than oversize.
c.
Extra consideration should be given in applications that require large amounts of cooling
in cold weather, such as buildings with a center or core area.
d.
Hot gas bypass should be considered on some commercial systems.
e.
If the HVAC unit is supplied with an economizer, it is recommended that the economizer
package be equipped with a relief air damper.
f.
The SlimZone Classic requires the use of motorized zone dampers, such as the A 24VAC 2
wire (powered closed, spring open) or 3 wire (powered closed, powered open) configuration.
g.
The pressure drop across typical zone dampers is negligible and normally not a factor
when sizing or calculating branch duct CFM.
h.
Typical zone control dampers are designed to work only with low pressure systems (1.0"
WC or less).
i.
Balancing dampers should be installed ahead of all motorized zone dampers.
j.
Zone dampers should be installed 10ft. (3m) back from discharge grille when possible.
k.
Flex or lined duct is recommended on the last 5ft. (1.5m).
l.
A bypass damper must be installed on all systems of three (3) zones. Some two (2) zone
systems may require a bypass damper.
m.
The thermostats and motorized dampers may be located up to 300ft. (90m) from the
control panel when 18AWG copper thermostat wire is used.
n.
This system requires standard electromechanical or electronic heat/cool thermostats. Do
not use heat pump thermostats because a call for compressor from the thermostats will be
recognized by the panel as a cool only call. The control algorithm in this panel is
configured such that heat pump thermostats are not required.
o.
The mode of equipment operation at the control panel is first determined by the signals
present on the C and H input terminals of Zone #1, then on the mode of operation of the
zone thermostat(s).
p.
To comply with Class 2 wiring code, the maximum load allowed to be switched by the
output terminals is 2.5 Amps.
q.
All outputs are protected by a current limiting device.
r.
System wires should be tagged to match the panel terminal designations.
s.
The addition of equipment heating and cooling limits, as provided by the HILO-200, is
strongly recommended and will greatly help in preventing temperature swings as well as
constant heating/cooling changeover.
t.
All zones served by a panel should have the same basic load characteristics.
u.
References to typical dampers in this manual are Robertshaw model dampers.
CAUTION
•
To avoid short cycling of equipment, always disconnect HVAC equipment from the control
panel before overriding time delay.
SlimZone Classic
2
