CEMP-E
TI 810-11
30 November 1998
element and transmitter located as shown. The DDC system shall start and stop the distribution pumps,
boiler pump, and boiler at the outside air temperatures shown. The DDC system shall reset the hydronic
heating supply temperature setpoint in a linear schedule based on the outside air temperature as shown.
The DDC system shall accept a signal from a temperature sensing element and transmitter located in the
hydronic heating supply line and the DDC system output shall modulate the hydronic heating system
control valve to maintain the reset schedule setpoint in the hydronic heating supply line.
(2) When the system time schedule places the system in the occupied mode, a space
temperature sensing element and transmitter located as shown shall signal the DDC system, which shall
maintain the space temperature setpoint shown by modulating the secondary hydronic system zone
valve.
(3) When the system is in the unoccupied mode, the space temperature setpoint shall be as
shown.
13. CENTRAL PLANT HIGH TEMPERATURE HOT WATER HYDRONIC HEATING CONTROL
SYSTEM.
a. Description of the hydronic heating system. This hydronic heating system consists of a high-
temperature hot water converter that provides hot water to a primary pumping system. The primary
pumping system supplies hot water to secondary pumping systems that provide hot water to separate
zones of space temperature control. Figures 4-9a through 4-9f show the system design for this type of
heating system using a SLDC control panel. Figures 4-9g through 4-9j show the system design for this
type of heating system using DDC controls.
Figure 4-9a. Control system schematic for central plant high-temperature hot water hydronic heating
system.
Figure 4-9b. Control system ladder diagram for central plant high-temperature hot water hydronic heating
system.
Figure 4-9c. Control system equipment for central plant high-temperature hot water hydronic heating
system.
Figure 4-9d. Control panel interior door layout for central plant high-temperature hot water hydronic
heating system.
Figure 4-9e. Control panel back panel layout for central plant high-temperature hot water hydronic
heating system.
Figure 4-9f. Control panel terminal block layout for central plant high-temperature hot water hydronic
heating system.
4-12
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