not less than 50 feet from any underground water pipes, utility lines, metal equipment
making contact with the earth, or grounding electrodes of any electrical system.
(ii) Determine which farm electrical panel serves the equipment or general
location of the animal contact location. This electrical panel shall be called the animal
building panel. The neutral-to-earth voltage at the animal building panel (NbEV) shall
be measured from the panel grounding terminal to the reference ground established in
subdivision (b)(i) of this subrule. This measurement can be used to validate that the
animal contact voltage (AcV) was not inadvertently disconnected or disturbed during
the 72-hour monitoring period.
(iii)
The neutral-to-earth voltage at the utility's primary distribution neutral
conductor (NpEV) shall be measured from the utility's primary neutral grounding
electrode conductor at the utility transformer serving the farm to the reference ground
established in subdivision (b)(i) of this subrule.
(c) Simultaneously measure and record the 3 steady state voltages, AcV, NpEV
and NbEV, for a period of 72 hours during a mutually agreed upon time frame. If more
than 1 instrument is used, then the instrument clocks shall be synchronized. The
following shall be used:
(i) The animal contact voltage (AcV) with a nominal 500-ohm shunt resistor
(R shunt) placed across the input leads of the voltage measuring instrument.
(ii) The neutral-to-earth voltage at the animal building panel (NbEV).
(iii) The neutral-to-earth voltage of the utility primary distribution system neutral
(NpEV) at the utility transformer serving the farm.
(3) Determine the utility contribution to animal contact current. This procedure
may be conducted using non-recording digital voltage measuring instruments. All of
the following apply:
(a) Examine the voltage recordings and locate the highest steady state value of
animal contact voltage (AcV) which will be called the animal contact test voltage (AcVt).
(b) Determine the steady state value of utility primary distribution system
neutral voltage (NpEV) that was present at the time the animal contact test voltage
occurred. This will be called the primary neutral-to-earth test voltage (NpEVt).
(c) Install 1 voltage instrument to measure the voltage of the utility primary
distribution system neutral to the reference ground (NpEV) and another voltage
instrument to measure the animal contact voltage (AcV) with a nominal 500-ohm shunt
resistor (R shunt) placed across the input leads of the voltage measuring instrument.
(d) Turn off all farm electrical loads while leaving the transformer energized
and leaving the secondary neutral conductor connected to the farm electrical system.
This can be accomplished by opening the main farm electrical disconnect and
removing the electric meter, or by some other effective means.
(e) Add a temporary load to the transformer (that does not utilize the secondary
neutral) until the primary neutral to reference ground test voltage (NpEVt) is achieved,
and record the animal contact voltage that occurs. This measurement will be called the
utility contribution to animal contact voltage (AcVu).
(f) If the primary neutral to reference test voltage (NpEVt) cannot be achieved as
described in subrule 3(e) of this rule, then the utility contribution to the animal
contact voltage (AcVu) will be determined by using the linear relationship between the
primary neutral to reference voltage
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