To use the 3M Heat Trace Bill of Materials Tool, visit
3M.ca/HeatTrace
To use the 3M Heat Trace Bill of Materials Tool, visit
3M.ca/HeatTrace
39
12" O.C. 9" O.C. 6" O.C.
Calgary, Alberta
Edmonton, Alberta
Halifax, Nova Scotia
Montreal, Quebec
Ottawa, Ontario
Quebec City, Quebec
St. Johns NFLD,
Sudbury, Ontario
Toronto, Ontario
Vancouver, B.C.
Winnipeg, Manitoba
40 45 50 55 60 65 70 75 80 85 90 95 100
Percentage of snowfall hours surface is clear with KSR™ Self-Regulating
Heating Cable heat tracing cable spacing as indicated
Cable Spacing Selection Guide
%
As an alternate to the KSR™ Self-Regulating Heating Cable spacing selection chart shown in Step 2 (page 34-35),
a snow and ice melting system can be designed using the information presented in Chapter 45 of the ASHRAE
Applications Handbook. In their tutorial on snow and ice melting, ASHRAE compiled a list of 33 Canadian cities with
weather data for each. Using this information, 3M developed the table below to show the effect of various power
(heat) outputs.
The values presented in Table 1, Data for Determining Operating Characteristic of Snow Melting Systems (ASHRAE
1991 Applications Handbook, Chapter 45), and detailed below in the
Cable Spacing Selection Guide chart,
show the
calculated percentage of snowfall hours that a surface will remain clear of snow when a predetermined level of heating
is installed. This method is useful when comparing what additional benefit, in terms of keeping an area clear, is obtained
when the watts/ft
2
are increased.
While it is necessary to have weather data to establish values for temperature, wind, humidity and snowfall, ASHRAE
cautions that a snow melting system should not be designed based on the annual averages or worst weather conditions
encountered. Doing so will result in a system unnecessarily over-designed for a majority of applications.
Cable Spacing Selection Guide
• The panel can utilize a main circuit breaker and contactor, which permits a complete shutdown of the system for
out-of-season times as well as routine maintenance checks.
• A dedicated snow melting panel will reduce the potential of non-authorized access.
• A dedicated snow melting panel can be located close to the point of use and reduce power feed wiring and conduit
necessary to energize the system.
• In critical snow melting applications, the panel can be equipped with a monitor and alarm feature that will verify the
integrity of the circuit and the status of the ground-fault branch circuit breakers.
Summary of Contents for TTS-5-1-OJ
Page 7: ...To use the 3M Heat Trace Bill of Materials Tool visit 3M ca HeatTrace 7 2 2 2 2 2 3 3 3 3...
Page 8: ...To use the 3M Heat Trace Bill of Materials Tool visit 3M ca HeatTrace 8 Pipe Freeze Protection...
Page 11: ...To use the 3M Heat Trace Bill of Materials Tool visit 3M ca HeatTrace 11 4 5 6 7 9 1 8 3 2...
