12-9. Multi-unit system ON/OFF conditions
In an Easy-Link system, the amount of T-H2-DV or T-H2-OS’s called on to activate depends on the FLOW
RATE and the SET TEMPERATURE.
1. Condition required to activate an additional T-H2-DV or T-H2-OS:
Flow rate required to activate additional T-H2-DV or T-H2-OS= A × n
Where n = number of currently activated T-H2-DV or T-H2-OS’s
and A is dependent on the set temperature. See table below:
Set temperature Factor “A"
˚F ˚C GPM L/min
100 - 120 38 - 49 3.4 13
125,130 52 - 54 3.2 12
140 60 2.9 11
145,150 63 - 65 2.6 10
155 - 185 68 - 85 2.4 9
2. Condition required to reduce the number of activated T-H2-DV or T-H2-OS’s:
A. In the case of reducing down from 2 T-H2-DV or T-H2-OS’s to one units T-H2-DV or
T-H2-OS: Flow rate = A / 1.7
B. All other cases: Flow rate = A × (n - 2)
3. Example: Set temperature = 120˚F in a four unit system and priority unit is No. 1
To activate additional
T-H2-DV or T-H2-OS’s
To reduce number of activated
T-H2-DV or T-H2-OS’s
Unit No.
Flow rate
Unit No.
Flow rate
GPM L/min
GPM L/min
No.1 ON 0.5 2.0