Specifications

Logamax plus GB142 applications manual | 01.2012
Technical specifi cations are subject to change without prior notice
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GB142 Applications Manual
Appendix 1 - Single boiler with 0-10V
heat demand input
A single boiler can be controlled via a quantified 0-10V heat
demand signal from a building management system. The EM10
module will read the 0-10V signal and modulate the boiler
according to:
(1) the system supply temperature
(2) power output
Control based on supply temperature
The EM10 uses the 0-10V signal of the building management
system to compute the system supply temperature set point.
This is a linear ratio (table 5).
Input
voltage
(V)
Flow temperature
set point
(boiler)
Status of
boiler
(°F) (°C)
0
32 0
OFF
0.5
32 0
OFF
0.6
± 59 ± 15
ON/heat demand
5.0
± 122 ± 50
ON/heat demand
10.0 ± 194
± 90
ON/heat demand
Table 5
Control based on boiler output
The EM10 uses the 0-10V signal of the building management
system to compute a performance set point. This is a linear ratio
(table 6).
Input
voltage
(V)
Performance set
point (boiler)
[%]
Status of
boiler
0
0
OFF
0.5
0
OFF
0.6
6
Low load *)
5.0
50 Part-load
10.0 100
Full load
Table 6
*) The low-load performance depends on the device type. E.g. if the low
load of the device is 20% and the control signal is 1 Volt (= 10%), the
performance value setting is lower than the low load. In this case the
boilers may be cycling on and off.
Voltage
Supply temperature °F (°C)
194 (90)
167 (75)
140 (60)
113 (45)
86 (30)
60 (15)
32 (0)
Figure 35 0 -10V Diagram
0%
30%
50%
100%
2
4
6
80
10
Voltage
System power output
Figure 36 Control based on power output