Installation manual

FuelMaster
®
Installation Manual
40
Conduit Requirements
CAUTION
Although PVC conduit is allowed by the NEC, only metal conduit will be used for FuelMaster
®
applications. Syn-Tech insists upon this because of non-metal conduit’s higher susceptibility to surge
(lightning) damage. Failure to use metal conduit and the recommended shielded cables voids all
warranties.
ATTENTION
Bien que le conduit de PVC soit permis par NEC, seulement le conduit en métal sera utilisé pour
l'équipement de FuelMaster
®
. Syn-Tech exige cela pour raison d'une susceptibilité plus élevée des
conduits non-métalliques aux dégâts causés par vague de courent (coup de foudre). Défaut
d'employer le conduit en métal et les câbles protégés recommandés vide toutes les garanties.
Many fuel distributors and electrical contractors prefer to use PVC conduit due to its cost, ease of
installation, and resistance to corrosion. There are several factors to be considered when using PVC
conduit. First the National Electric Code, Article 514 (Gasoline Dispensing and Service Stations)
states that if PVC is used in a hazardous location it must be at least 2 feet below surface and metal
conduit must be used to surface from the 2 foot depth. It is possible to meet NEC requirements
using PVC when the correct type of conduit is used in emergence.
The main problem with PVC is that the ground plain of wiring inside PVC goes up and down based
on the adjacent ground, and is not protected as is wire inside metal conduit. Wire inside PVC that
receives a surge or ground differential will transmit that in both directions, first to the FMU and
secondly to whatever is connected to the other end of the wire.
All wires and cables used by the FuelMaster
®
equipment must be routed through rigid metal conduit
approved by, and installed in accordance with, the National Electric Codes (NEC), NFPA 70. This is
a common requirement among reputable manufacturers of fuel management systems and fuel
dispensing equipment. The requirement to use metal conduit is for the customer's benefit.
FuelMaster
®
will warrant your FMU in accordance with its stated warranty which covers defective
parts, telephonic support, etc., but not Acts of God. Lightning strikes/surges are considered Acts of
God, and are not warranted.
If it is not possible to comply with the requirement for rigid metal conduit, contact Syn-Tech Systems.
Acceptable workarounds may be available.
Conduit Size. The recommended conduit size is 3/4 inch. Wire sizes and quantities permitting, a
limited number of 1/2 inch conduit may be used. The FMU pedestal bulkhead can accept up to ten
3/4-inch conduits and four 1/2-inch conduits. Larger and smaller conduit may be adapted to fit the
FMU pedestal bulkhead.
The number of required conduit will be dependent upon the application, and the number of connected
Satellite FMUs, EIUs, fuel dispensers, and options. If the number of conductors exceeds the conduit
fill capacity, additional conduit must be used.
Conduit Fill Capacity. The NEC states conduit will not be filled to greater than 40% fill capacity.
If the conduit terminates in a seal-off, seal-offs cannot exceed 25% fill capacity. Table 1 shows the
available area within different size rigid metal conduit at full, 40%, and 25% capacity. Table 2 shows
the cross sectional area of different wire sizes used with an FMU or EIU installation. You can
estimate the NEC requirement by adding the cross sectional area of all the wires you intend to pull
through a conduit, then comparing it to the maximum (40% or 25%) fill capacity of the conduit being
used. If you are exceeding the fill capacity, additional or larger conduit will be necessary.
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