Application Brochure

© 2009 A 664 - 12/09 8 of 12
Concept Drawing This is only a concept drawing, not an engineered drawing. It is not intended to describe a complete system, nor any particular system. It is up to the system designer to determine the necessary components for and configuration of the particular system being designed, including additional equipment, isolation relays (for loads greater than the control’s specified output ratings), and any safety devices which in the judgement of the designer are appropriate, in order to properly size, configure and design that system and to ensure compliance with building and safety code requirements.
tekmar Control Systems Ltd., Canada; tekmar Control Systems, Inc., U.S.A.; www.tekmarcontrols.com
Head Office: 4611-23rd Street, Vernon, B.C. Canada, V1T 4K7; [phone] Fax [phone]
- Application
Mechanical
A 664-4
12/09
see Essay E 021
Outdoor Sensor (S6) 070
120 V (ac)
V1
P3
P4
P2 P1
D1
Mix Return
Sensor (S3) 082
Mix Supply
Sensor
(S2) 082
Boiler Supply
Sensor (S1)
082
Slab Sensor
(S4)
072/073
Snow/Ice
Sensor
(S5) 090
664
D1 = External Melt / Idle Demand P1 = Primary Pump P2 = Variable Speed Injection Pump P3 = Zone 1 Pump P4 = Zone 2 Pump S1 = Boiler Supply Sensor 082 S2 = Mix Supply Sensor 082 S3 = Mix Return Sensor S4 = Slab Sensor 072/073 S5 = Snow / Ice Sensor 090 S6 = Outdoor Sensor 070 V1 = Balancing Valve or Globe Valve
System Operation The Snow Detector & Melting Control 664 provides snow melting for a two zone system. The 664 operates the boiler based on the current load on the system in order to provide the required mixed supply fluid temperature that satisfies the load while protecting the slab from thermal stress. The output of the variable speed injection pump (P2) is controlled in order to protect the boiler from flue gas condensation.