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INTRODUCTION
1 Scope
1.1 These requirements cover fixed and stationary power converters, power-converter systems, and
accessories having a rated nominal input of 120, 120/240, or 240 volts, alternating current and a nominal
output of 24 volts or less, direct current. These converters are intended for use within land vehicles where
not directly exposed to outdoor conditions, and are intended to be employed in accordance with the
National Electrical Code, NFPA 70.
1.1 revised October 15, 2004
1.2 These requirements also cover fixed, stationary and portable power inverters and power-inverter
systems having a dc input and a 120 or 240 volts ac output. These inverters are intended for use within
land vehicles where not directly exposed to outdoor conditions, and are intended to be employed in
accordance with the National Electrical Code, NFPA 70.
1.2 effective April 13, 1993
1.3 These requirements also cover converters/inverters that are additionally intended to charge batteries.
1.3 effective April 13, 1993
1.4 Power converters covered by Part I of this standard are intended for connection to established 15-
and 20-ampere branch circuits within a recreational vehicle.
1.5 Power-inverters covered by Part I of this standard are intended for connection to a 12- or 24- volt dc
battery supply.
1.5 effective April 13, 1993
1.6 Power-converter systems and power-inverter systems covered by Part II of this standard are intended
for direct connection to a power-supply assembly and incorporate means for the connection of a maximum
of three line-voltage branch circuits only, not including the main disconnect. Power converter systems and
power inverter systems also employ circuitry as described in 1.4, and 1.5, or 1.5.
1.6 revised October 15, 2004
1.7 Power-converter systems and power-inverter systems shall also comply with the applicable
requirements for a Class CTL panelboard in the Standard for Panelboards, UL 67.
1.7 revised October 15, 2004
1.8 Converters and inverters incorporating provisions for the connection of more than three line-voltage
branch circuits are judged under the requirements in Part I of this standard and the applicable
requirements for a Class CTL panelboard in accordance with the Standard for Panelboards, UL 67.
1.8 effective April 13, 1993
1.8.1 Each pole of a multiple-pole circuit breaker is a separate circuit.
1.8.1 added October 15, 2004
1.9 A product that contains features, characteristics, components, materials, or systems new or different
from those covered by the requirements in this standard, and that involves a risk of fire, electric shock, or
injury to persons shall be evaluated using the appropriate additional component and end-product
requirements to determine that the level of safety as originally anticipated by the intent of this standard is
maintained. A product whose features, characteristics, components, materials, or systems conflict with
OCTOBER 15, 2004 UL 458 7
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