Specifications

PIP ELCGL01
November 2002 Electrical Design Criteria
Process Industry Practices Page 19 of 20
14.2 Heat-tracing system components shall be supplied as specified on the Data Sheet.
14.3 The heat-tracing systems include power transformers, electric heat trace control
panels, electric heat cables, temperature sensors, temperature controllers, circuit
breakers, enclosures, conduit, wire, insulation, and all necessary auxiliary equipment
and controls.
14.4 Electric heat-tracing control panels, power transformers, and power distribution
equipment shall be centrally located to minimize the lengths of heating power
circuits in the area.
14.5 All tracing design shall utilize a minimum of 25% safety factor in calculated heat
input. Heat loss calculation shall be submitted to verify compliance.
14.6 Installation of the heating cable, components, and controls shall begin after pressure
testing of the pipeline and installation of all the instruments. Thermal insulation shall
not be installed until the electrical installation and testing is complete.
14.7 Heat tracing for pipes shall include all inline components. All flanges, pumps,
valves, devices, supports, and appurtenances shall be traced with appropriate
additional lengths of heater cable as required to allow equipment removal without
disconnecting and removing the heat tracing.
14.8 Heater cable design shall be suitable to deliver rated performance and service life
when subjected to voltage variations from 90% to 110% of nominal distribution
voltages.
14.9 Components of the electric heat-tracing systems shall be approved for the area
classification in which they are installed.
14.10 Heating requirements and sectionalizing shall be coordinated with process
requirements.
14.11 Each heat-tracing circuit shall be equipped with a suitable device for isolation and
installation of a lockout device.
15. Cathodic Protection
Cathodic protection, when required, will be specified separately.
16. Uninterruptible/Standby Power Supply
16.1 Critical power supply systems shall be designed as shown on the Data Sheet.
16.2 When specified on the Data Sheet, an uninterruptible power supply (UPS) shall be
provided and sized to accommodate the process control loads plus 20% spare
capacity. The UPS shall have its own dedicated battery and distribution panel. A
separate detailed specification shall be issued for the UPS system if required. When
specifying a UPS system, refer to PIP ELSAP03 and PIP ELSAP04. The UPS battery
type shall be flooded cell as specified in PIP ELSAP15 unless specified otherwise on
the Data Sheet.