King Electric TCM - Manual (Page 6)

SAVE THESE INSTRUCTIONS
INSTALLATION—SAND BED APPLICATION
STEP 4: MEASURE THE RESISTANCE OF THE HEATING CABLE
Using a digital ohm-meter, measure the resistance of the TC cable. Compare the measured value with the resistance listed on the label of the
power lead.
Remember to record the measured resistances on TC Cable / TCM Mat Testing Log under the section “Test Record # 1 Before Installa-
tion”. Documenting the resistance at each stage of the installation is required for warranty purposes.
STEP 5: INSTALLING THE TC/TCM CABLE/MAT
Install the TC/TCM cable/mat according to the sketch made in Step 1. The cable/mat should be secured to prevent movement in subsequent
steps. Follow instructions under section “Installing the Cable / Mat” on page 4.
At least 12 inches (30 cm) of the power lead must be embedded in the mass material. The remainder of the power lead should be in a conduit
that extends to the thermostat or contactor. The power lead may be extended if required.
Measure the resistance once again, and record in the TC Cable / TCM Mat Testing Log under the section “Test Record # 2 During Installa-
tion”.
IMPORTANT TIP: It is recommended to take a picture of the cable/mat layout and conduit placement during installation. This can help in
the unlikely case that the cables/mats need repairs.
STEP 6: FINISHING THE SAND BED
Continue raising the sand bed with washed masonry sand, to approximately 1inch below the base of the future concrete slab. Once again sand
should be free of organic material, stones, debris or any other object that could damage the TC cables. Gently wet the compacted sand until
completely saturated with water.
Ensure that the contractors are careful not to damage the cable with tools, heavy machinery, etc.
Install a vapor barrier over the sand bed with 6 inches of overlap for adjacent sheets. Finish the sand bed with an additional 1 inch of compact-
ed sand. This will help to prevent movement of the vapor barrier when during subsequent steps.
Measure the resistance once again, and record in the TC Cable / TCM Mat Testing Log under the section “Test Record # 3 After Installa-
tion”.
It is not recommended to power the cable at this time.
STEP 7: POUR THE CONCRETE SLAB
Pour the concrete slab. Ensure that the contractors are careful not to damage the cable with tools, heavy machinery, etc. Once the slab is
poured but concrete is still wet, measure the resistance once again, and record in the TC Cable / TCM Mat Testing Log under the section
Test Record # 3 After Installation”.
It is not recommended to power the cables/mats for until the concrete has cured (approximately 30 days). Check with the concrete manufactur-
er for exact curing times. Doing so can affect both the integrity of the slab, and the subsequent proper operation of the TC/TCM cables/mats.
STEP 8: CONNECT POWER SUPPLY AND THERMOSTAT
The connection of the thermostat must be done by a qualified electrician familiar with heating cables and in accordance with the National Elec-
trical Code (NEC) and the Canadian Electrical Code (CEC). Remember to properly ground the heating cable braid.
If this is not already done, the sensor should be installed in the conduit. Remember that the sensor should reach the sealed end of the conduit.
Connect the thermostat and sensor according to the wiring diagram in appendix A.
A final resistance reading of the cables should be carried out, and recorded in the TC Cable / TCM Mat Testing Log under the section “Test
Record # 4 Final Commissioning”.
KING ELECTRIC MFG CO · 9131 10TH AVENUE SOUTH · SEATTLE, WA 98108 · PH:206 762 0400 · FAX: 206 763 7738 · www.king-electric.com