Manual 2100-746D
Page
27 of 59
FIGURE 10
Cooling with Six Single Stage Units (w/Economizers) Using Twinning/Pairs Option
The Advantages of Twinning: Pairs
Using the same number of units as shown in Figure 9
(six units w/economizers) and selecting the
Pairs
option
in
Twinning
, the number of stages can be reduced to
six by engaging two units per stage (see Figure 10).
This reduces the temperature range in the building by
50% as well (5°F).
FIGURE 11
Cooling with Six Single Stage Units (w/Economizers) Using Twinning/Triples Option
By pairing units, the temperature spread to bring on all resources goes from 11°F down to 5°F.
78.0
80.0
82.0
74.0
76.0
Stage 1
75.0
77.0
79.0
81.0
83.0
Stage 2
Stage 3
Stage 4
Stage 5
Stage 6
Cooling
Cooling Deadband
Off
Defaults
Setpoint: 77°F
Interstage Differential: 1°F
Off Differential: 2°F
The Advantages of Twinning: Triples
Using the same number of units and selecting the
Triples
option in
Twinning
, the number of stages can be
reduced to four and the space temperature narrowed
even more, from singles (77°F to 88°F, 11°F total)
to pairs (77°F to 82°F to, 5°F total) to triples (77°F
to 83°F, 3°F total) as shown in Figure 11. Be sure to
consider the total number of stages and choose the
best option for the application.
78.0
80.0
82.0
74.0
76.0
Stage 1
75.0
77.0
79.0
81.0
83.0
Stage 2
Stage 3
Stage 4
Cooling
Cooling Deadband
Off
Defaults
Setpoint: 77°F
Interstage Differential: 1°F
Off Differential: 2°F