Gasboy Atlas Fuel Systems Site Prep Manual - Manual (Page 17)

MDE-4333E Atlas Fuel Systems Site Preparation Manual · November 2011 Page 13
Electrical Requirements Site Preparation
• Make the emergency power cutoff switch accessible, label it clearly, and install it away
from any hazard that may occur at the pumps/dispensers. Do not install cutoff switches
more than 100-feet away from the pumps/dispensers.
• Show all employees where the emergency power cutoff switch is located and how to use
it. Remind them often.
Notes: 1) Do not use E-STOP, ALL-STOP, or PUMP STOP keys on Gasboy console/cash
registers to shut-off pump/dispenser power. These keys do not remove AC power and
do not always stop product flow.
2) Daisy Chain Wiring is used to reduce wiring cost. However, it is not recommended
as it results in loss of power to all pumps in the event of one bad wire or bad
connection. Wiring shown in this manual is for non-daisy chain applications.
Units with Ground Fault Interrupt (GFI)
GFI Breakers are required for DEF dispensers mounted on Skid Tanks because of no
underground piping, AC power in potentially wet area, and a potential for earth ground to
break if Skid Tank moves.
A GFI consists of a sensor that detects changes in the current to the load, by comparing the
current flowing to the load and the current flowing from the load. A drop-off in the current
equivalent to about 5 milliamperes, turns off all power by tripping a relay within the GFI
within a few hundredths of a second.
When powering a dispenser with a GFI, the return neutral of any device to which the dispenser
supplies power must be the same neutral as that of the dispenser. For example, the STP control
relay.