Frost Heave
Prevention System:
Heating System shall consist of Self-regulating cable
mounted in rigid conduit below the insulation in the Mud Slab or aggregate. System
shall be controlled and monitored by a processor based controller that Controls,
Monitors, Alarms, and provides troubleshooting information as standard design.
1) System Provider:
a.
System provider shall be experienced in Frost
Heave Prevention System with over 35 years’ experience in design, installation,
startup and troubleshooting.
b.
Provide detailed Layout drawings
c.
Provide Electrical details and electrical
drawings.
d.
Provide Complete installation and startup
instructions.
e.
Provide replacements parts list with standard
off the shelf replacement part numbers.
f.
Provide a Detailed Check Out form for startup.
g.
Provide a 2 year warranty on the Control system.
h.
Provide a 1 year warranty on the Heat Cable.
i.
Acceptable manufactures Thermal Equipment Sales
Co. Inc. Memphis Tn. 901-452-4516
2) Floor Heating Cable:
a.
Cable shall be Self-regulating Low temperature
cable, wattage rating per spec.
b.
Cable shall operate at an equilibrium
temperature of 50º F at the rated wattage and regulate temperature all along
the entire length.
c.
Construction:
i. industrial
grade 16AWG buss wire
ii. tinned
copper braid for a grounding conductor
iii. Fluoropolymer
over-jacketing, ensuring operating integrity for corrosive and heavy moisture
laden industrial environments.
iv. Heating
cable should have a maximum maintenance temperature rating of 150°F (65°C).
v. UL
Listed for ordinary areas and fire protection system piping.
vi. FM
Approved for ordinary and hazardous areas
vii. Maximum
circuit lengths shall be calculated at 32º F
d.
Terminations:
i. Shall
be made with Silicone End Power Connection kits on both ends of cable
ii. Tinned
copper overjacket shall be grounded per code
iii. The heating cable shall be supplied with a High
temperature Silicone sealant, to provide a moisture seal where the Cable
penetrates the junction box.
iv. Junction
Termination box shall be a Metal Weather Proof Enclosure(s) with screw cover that
has 4” square minimum dimensions. Provided by others.
3) Processor based Floor Monitor and Control
System shall Monitor, Control and Alarm all facets of the Frost Heave
protection system.
a.
Control System shall operate Heat Trace Cable at
a user determined design temperature (minimum setpoint 32ºF). Control setpoint and temperature alarm are
field accessible.
i. Summer
Peak Utility control input shall cycle the design temperature to provide a
lower heat output during peak operating times. Provided by a user supplied
remote digital input (24 VDC).
ii. Hardware
1.
Modicon PLC 40 I/O
with Thermocouple input module
2.
256 kB memory internal RAM
3.
Battery Backup (standard over the shelf battery
replacement)
4.
Internal Data backup 256 kB built-in flash
memory backup of application and data
5.
2 GB SD card (optional)
6.
USB port
7.
Ethernet port and Modbus ports
8.
GFI Circuit protection (all circuit protection
shall be rated for inrush current)
9.
Monitor GFI breakers for Personal and Equipment
safety 40 amp 30 mA
10.
Branch circuit protection, Supplementary
Protectors Class UL1077
11.
Solid State relays rated for inrush current
12.
Main Disconnect with Lock out / Tag out Door
interlocking mechanism
13.
Control transformer fused primary and secondary
protection
14.
Low voltage power supply rated at 60 watts 24
volts
15.
5.7” Color HMI Monitor shall be rated NEMA 4X
for indoor wet and corrosive environments
16.
NEMA 12 Enclosure
iii. Monitoring
shall include fault history for each variable, with troubleshooting tips, and
replacement part numbers for specific installation. Each alarm shall clearly indicate the
location and circuit affected.
1.
Temperature, with low temperature alarm, per
Circuit
2.
GFI for ground fault conditions
3.
Branch Circuit fault conditions
4.
End of run monitor for Continuity
5.
Thermocouple Lead break protection
iv. Alarm
Outputs
1.
Alarm output 24 Volt DC for user DCS System or
external monitoring
2.
Ethernet connection for Remote monitoring
3.
Timed monitoring of system Circuits in
temperature alarm conditions
4.
Sensor lead break protection
5.
90 DB Alarm Horn shall have an alarm silence
push button and 24 hour restart until system fault(s) are corrected.
6.
Flashing Red Beacon indicates Alarm Conditions
v. Control
system shall come complete and pretested for easy field startup with all
control outputs and inputs terminated at clearly labeled terminal strips.
4) Installation:
i. Install electric heating cable according to the drawings and the manufacturer’s instructions.
ii. The installer shall
be responsible for providing a complete functional system,
installed in accordance with applicable national and local requirements.
iii. Grounding of controller shall be performed according to Section 26 05 26 "Grounding and Bonding for Electrical”
iv. INSTALLATION
TESTING
1.
When the heater cable and connections for a
circuit have been completed, immediately perform the following checks:
a.
Visually inspect the heater cable. If damage is
seen, either replace the complete heater cable, or cut out the damaged section.
(no splices shall be made in conduit)
b.
Inspect all connections to be sure they are
correctly assembled. Be sure each heater cable entry to a connection has a
moisture resistant seal and caps are properly installed.
c.
Inspect the insulation resistance of the circuit
using a 500VDC megger. Always perform this test at the power connection. Any
cable with an insulation resistance of less for than 10 megohms should be
removed and discarded.
d.
Check voltage at end of circuit and record in
log on the Detailed Check-out Form. Systems with End of run continuity monitoring
check for relay operation when energized.
Check amperage and on each cable at startup and again in 30 minutes,
record amperage for future Preventive maintenance checks. Verify all alarms are engaged as per Checkout
form.
