Application Brochure

© 2009 A 664 - 12/09 4 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
Outdoor Sensor (S5) 070
120 V (ac)
Class 2
Transformer
24 V (ac)
D1
P2
C1
P1
V1
M
664
Mix Return
Sensor
(
S3
)
082
Mix Supply
Sensor
(S1) 082
Boiler Supply
Sensor
(S2) 082
Snow/Ice
Sensor
(S4) 090
A 664-2
12/09
C1 = Actuating Motor 741 D1 = External Melt / Idle Demand P1 = Boiler Pump P2 = Zone 1 Pump S1 = Mix Supply Sensor 082 S2 = Boiler Supply Sensor 082 S3 = Mix Return Sensor 082 S4 = Snow / Ice Sensor 090 S5 = Outdoor Sensor 070 V1 = 4-Way Mixing Valve
System Operation The Snow Detector & Melting Control 664 provides snow melting for a single zone system. The 664 stages the boilers 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 position of the mixing valve is controlled in order to protect the boilers from flue gas condensation