Application Brochure
Product design, software and literature are Copyright © 2000 by:
tekmar Control Systems Ltd. and tekmar Control Systems, Inc.
tekmar Control Systems Ltd., Canada
tekmar Control Systems, Inc., U.S.A.
Head Office: 5100 Silver Star Road
Vernon, B.C. Canada V1B 3K4
Tel. (250) 545-7749 Fax. (250) 545-0650
Web Site: www.tekmarcontrols.com
Control Systems
System Operation
All specifications are subject to change without notice.
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A 356-5 05/00
Printed in Canada. A 356-5 05/00.
The Mixing Control 356 provides setpoint control to fancoil zones. The output of the variable speed injection pump is modulated to
provide a fixed water temperature to the zones, and protect the boiler from flue gas condensation. The boiler operates at the required
temperature in order to satisfy the load.
Heat Source Details The heat source can be either a high mass or low mass non-condensing boiler.
Piping Details Fancoil units are piped into the mixed loop. The variable speed injection pump (P1) is piped in primary / secondary in
order to isolate the boiler loop flow rate from the mixed loop flow rate. The boiler pump (P2) provides flow through the boiler and ensures
flow past the variable speed injection pump take-off.
Mixing Demand When heat is required in the mixed zones, the mix demand switch provides a
Mixing Demand
to the 356. The mixed
supply water temperature is fixed based on the MIX TARGET setpoint. The variable speed injection pump (P1) is then controlled to
supply the required mixed supply water temperature. As the variable speed injection pump ramps up and requires more heat from the
boiler, the boiler is fired to a temperature that is sufficient to satisfy the requirements of the variable speed injection pump. Whenever the
boiler is fired, the 356 aims to maintain the boiler temperature above the BOIL MIN setting. While the boiler is firing, the variable speed
injection pump is also modulated to protect the boiler from excessively low water temperatures.
All control functions and specifications are listed in the Product Catalog I 000 and Data Brochure D 356.