GE Industrial Solutions GE A-Series 9îand 24î Panel Box User Manual
Page 5
2020000604 (12/09) Page 5 of 15
M
AXIMUM
C
ONTINUOUS
O
PERATING
V
OLTAGE
(MCOV)
This value defines the maximum line-to-line or line-to-neutral continuous AC voltage that can be
safely applied to the protector. MCOV levels for GE TR7000 Series SPDs are set at 115% of nominal
system voltage. For 120-volt AC systems, the MCOV is 125%. If there is a risk that the electrical
system voltage could exceed MCOV, or if any unusually high power frequencies, Temporary Over
Voltages (TOV), or phase swells are anticipated, contact your GE Sales Engineer for further
assistance.
E
LECTRICAL
S
YSTEM
C
ONFIGURATION
Protectors are available for single (split) phase with neutral and ground, three-phase grounded WYE,
three-phase ungrounded WYE, three-phase high-leg delta, and for three-phase ungrounded delta
systems. (See page 7 for power source configurations)
P
EAK
I
MPULSE
R
ATING
Peak surge current capability is an important characteristic for a SPD. The rating per mode should
equal or exceed the maximum surge expected in service. GE TR7000 SPDs are available in
maximum surge ratings of 65kA, 80kA, 100kA, 125kA, 150kA, 200kA and 300kA.
UL 1449 N
OMINAL
D
ISCHARGE CURRENT
(In)
The UL Nominal Discharge Current (In) rating should be considered when an SPD is selected for use
within a UL96A Lightning Protection System. UL96A requires a Nominal Discharge Current (In)
rating of 20kA for Type 1 or Type 2 SPDs.
S
HORT
C
IRCUIT
C
URRENT
R
ATING
GE TR7000 type SPD units with surge ratings of 125kA to 300kA per mode are UL certified for use on
electrical systems with rated ampacities up to 200,000 symmetrical amperes maximum. TR7000
type SDP units with surge ratings of 65kA to 100kA are UL rated for systems up to 100,000 A.
E
NVIRONMENTAL
R
ATINGS
The SPD is provided in a NEMA 1 Rated Panelboard extension enclosure and is designed to operate
within an ambient temperature range of –40
o
C to 65
o
C (-40
o
F to 149
o
F) with a relative humidity
level between 0-95% non-condensing.
A direct lightning strike, that occurs within close proximity of an installed SPD, can result in
surge currents that exceed the SPD’s energy handling capability. This can result in reduced
life expectancy or pre-mature failure of the SPD. Electrical power system supply voltages in
excess of the SPD MCOV rating, can also cause SPD failure.
Should a condition occur that results in premature failure of the SPD, the suppression
circuitry will short, thereby allowing the integral SPD fusing to interrupt current flow without
disrupting power to the connected loads. However, after SPD failure, the load equipment will
remain unprotected from subsequent surge activity until the SPD is replaced.
Increased rate of rise or higher surge current magnitudes can result in increased surge let-
thru levels due to the non-linear clamping characteristics of SPDs. Conditions can occur
where the surge withstand capability of the protected equipment is exceeded even though
the SPD is functioning properly. In such cases, additional SPDs may be required, located
closer to the sensitive load(s). (For additional information, refer to Standard IEEE 1100-2005,
Section 3.4.3)
GE TR7000 ETP Series WYE-connected SPDs have both normal mode (L-N, L-L) and common
mode (L-G, N-G) protection. Protection between neutral and ground is provided on units
designed for WYE-connected applications.