To use the 3M Heat Trace Bill of Materials Tool, visit
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To use the 3M Heat Trace Bill of Materials Tool, visit
3M.ca/HeatTrace
17
Maximum Circuit Length vs. Breaker Size – 240 Vac
Service Voltage feet (meters)
Maximum Circuit Length vs. Breaker Size – 120 Vac
Service Voltage feet (meters)
TTS 5-1
TTS 8-1
TTS
10-1
Circuit Breaker Size
Cable
Type
Start-Up
Temp.
30 A
20 A
15 A
°C (°F)
40 A
10 (50)
-18 (0)
-29 (-20)
-40 (-40)
180 (55)
155 (47)
140 (43)
125 (38)
240 (73)
205 (62)
185 (56)
165 (50)
285 (87)
285 (87)
275 (84)
250 (76)
285 (87)
285 (87)
285 (87)
265 (81)
10 (50)
-18 (0)
-29 (-20)
-40 (-40)
145 (44)
115 (35)
100 (31)
90 (27)
195 (59)
150 (46)
135 (41)
120 (37)
240 (73)
225 (69)
200 (61)
180 (55)
240 (73)
240 (73)
240 (73)
215 (66)
10 (50)
-18 (0)
-29 (-20)
-40 (-40)
120 (37)
85 (26)
75 (23)
70 (21)
160 (49)
115 (35)
100 (30)
90 (27)
200 (61)
170 (52)
150 (46)
135 (41)
200 (61)
200 (61)
200 (61)
180 (56)
TTS 5-2
TTS 8-2
TTS
10-2
Circuit Breaker Size
Cable
Type
Start-Up
Temp.
30 A
20 A
15 A
°C (°F)
40 A
10 (50)
-18 (0)
-29 (-20)
-40 (-40)
365 (111)
295 (90)
260 (79)
240 (73)
485 (148)
395 (120)
350 (107)
315 (96)
385 (117)
285 (87)
255 (78)
230 (70)
585 (178)
585 (178)
525 (160)
475 (145)
585 (178)
585 (178)
585 (178)
535 (163)
10 (50)
-18 (0)
-29 (-20)
-40 (-40)
290 (88)
215 (66)
190 (58)
170 (52)
485 (148)
430 (131)
380 (116)
345 (105)
485 (148)
485 (148)
480 (147)
480 (147)
10 (50)
-18 (0)
-29 (-20)
-40 (-40)
240 (73)
170 (52)
150 (46)
135 (41)
320 (98)
225 (69)
200 (61)
180 (55)
405 (123)
340 (104)
305 (93)
275 (84)
405 (123)
405 (123)
405 (123)
365 (111)
Table 1.3.2
Table 1.3.3
Example:
Continuing with the first example
from page 10, the 4" diameter metallic pipe
is 60' long, has one screwed valve and is
supported by 6 metal pipe hangers. The
heating cable allowances for the circuit
would be as follows:
Pipe Length:
60'
1 power connection: 1'
1 valve:
4'
6 pipe supports:
4' (4" dia. x 2 = 8"/hanger)
Total circuit length: 69'
Table 1.3.1: Valve and Pump Allowances
Valve Allowance
Pump Allowance
Pipe Size Screwed
Flanged
Welded
Screwed
Flanged
1/2"
6"
1'
0
1'
2'
3/4"
9"
1' 6"
0
1' 6"
3'
1"
1'
2'
1'
2'
4'
1-1/4"
1' 6"
2'
1'
3'
4' 6"
1-1/2"
1' 6"
2' 6"
1' 6"
3'
5'
2"
2'
2' 6"
2'
4'
5' 6"
3"
2' 6"
3' 6"
2' 6"
5'
7'
4"
4'
5'
3'
8'
10'
6"
7'
8'
3' 6"
14'
16'
8"
9' 6"
11'
4'
19'
22'
10"
12' 6"
14'
4'
25'
28'
12"
15'
16' 6"
5'
30'
33'
14"
18'
19' 6"
5' 6"
36'
39'
Table 1.3.1 A: Other Allowances
Description
Allowance
Power
Connections
1 foot of TTS™ Self-Regulating Heating Cable
for each heating circuit
Splices
2 feet of TTS™ Self-Regulating Heating Cable
for each splice kit
3 feet of TTS™ Self-Regulating Heating Cable
for each TSplice kit
Insulated Pipe
Supports
Require no additional heating cable
Uninsulated Pipe
Supports
Allow 2 times the length of the pipe support
plus an additional foot of heating cable for
each support