Echelon LONWORKS PLT-22, User Manual

Page: 49 / 128

Table 4.1 Line-to-Neutral Coupling Circuit Surge Immunity Test Results
Ring Wave Test
(0.5µs-100kHz)
Combo Wave Test
(1.2/50µs-8/20µs)
Product
Location IEEE C62.41-1991
system exposure
level Surge level
verified not to
damage PLT-22 IEEE C62.41- 1991
system exposure
level Surge level
verified not to
damage PLT-22
Branch Circuit low -2kV @70A
med-4kV @130A
high-6kV @200A
6kV @200A
Not specified
6kV @500A
2kV @1,000A
Power Entry low -2kV @170A
med-4kV @330A
high-6kV @500A
6kV @500A low -2kV @1,000A
med-4kV @2,000A
high-6kV @3,000A
6kV @3,000A
Outdoor Wiring
Not specified
6kV @500A low -6kV @3,000A
med-10kV @5,000A
high-20kV @10,000A 6kV @3,000A
(limited by test
equipment)
Surge protection with line-to-earth coupling is often constrained by the need to
maintain low leakage current. A varistor connected between line and earth adds
leakage current that may result in violation of applicable safety standards. This use
of a varistor for surge protection in line-to-earth coupling circuits is often prohibited.
Adequate surge immunity in branch circuit applications may be achieved without
varistors by the use of an X2-type capacitor instead of a non-safety rated metalized
polyester-type in the C1 location in line-to-earth coupling circuits. Surge immunity
may be further enhanced in power entry and outside wiring applications by the
addition of a gas tube surge arrester between line and earth.
If a gas tube surge arrestor is used between line and earth, the arrestor will have to
be loaded on the PCB after hi-pot testing. Hi-pot testing between line and earth is
usually performed at voltages above the break-down voltage of gas tube surge
arrestors, and the test will fail if a gas tube surge arrestor fires during testing.
The line-to-earth coupling circuits documented later in this chapter have been
demonstrated to meet the IEEE C62.41-1991 "medium system exposure" levels with
no damage for branch circuit applications , and the "high system exposure" levels
with no damage for power entry applications and for outdoor wiring applications (up
to the limits of the available test equipment).
L
ON
W
ORKS
PLT-22 Transceiver User’s Guide 4-15