Install in parallel, within the power distribution board or directly on the supply feeding the equipment.
At distribution boards, the protector can be installed either on the load side of the incoming isolator, or on the closest outgoing way to the incoming supply. Connect, with very short connecting leads, to positive, negative and earth.
On supplies over 100 amps, phase/live connecting leads should be fused with either 63 or 100 amp high rupture capacity (HRC) fuses, a switch fuse, MCCB or type"C"MCB.
Parallel connection of ESP 48 DC.
Suitable accessories
If the protector cannot be incorporated within the panel, use the WBX 3 enclosure.
Electrical specification
ESP 12 DC
ESP24 DC
ESP36 DC
ESP48 DC
Nominal voltage (RMS)
12V
24V
36V
48V
Working voltage (RMS)
9-15V
18 - 30V
27 - 45V
36 - 60V
Current rating (supply)
Direct connection to supplies
up to 100A
Connection via series fuses to supplies greater than 100A
See installation instructions
Leakage current (no earth)
<250µA
<250µA
<250µA
<250µA
Indicator circuit current
<10mA
<10mA
<10mA
<10mA
Volt free contact*
-current rating
-nominal voltage (RMS)
Screw terminal
-1A
250V
Screw terminal
1A
250V
Screw terminal
1A
250V
Screw terminal
1A
250V
Transient specification
ESP 12 DC
ESP24 DC
ESP36 DC
ESP48 DC
Let-through voltage (all conductors)
6kV 1.2/50µs open circuit voltage
3kA 8/20µs short circuit current to:
BS 6651:1999 Appendix C, Cats C-Low & B-High
IEEE C62.41 - 1991² Location Cats C1 & B3
SS CP 33:1996 Appendix F
AS 1768 - 1991 Appendix B, Cat B
UL1449 mains wire-in
<120V
<120V
<120V
<120V
Maximum surge current²
20kA
20kA
20kA
20kA
1 The maximum transient voltage let-through the
protector throughout the test (+/-5%), phase to neutral, phase to earth
and neutral to earth.
2 Formerly IEEE 587 and ANSI C62.41.
3 Tested with 8/20µs waveshape to BS 6651:1999 Appendix C. Note:
The electrical system, external to the unit, may constrain the actual
current rating achieved in a particular installation.
Mechanical specification
ESP 12 DC
ESP24 DC
ESP36 DC
ESP48 DC
Temperature range
-25°C +70°C
-25°C +70°C
-25°C +70°C
-25°C +70°C
Connection type
Screw Terminal
Screw Terminal
Screw Terminal
Screw Terminal
Conductor size (stranded)
16mm³
16mm²
16mm²
16mm²
Earth connection
Screw Terminal
Screw Terminal
Screw Terminal
Screw Terminal
Volt free contact
Connect via screw terminal with
conductor up to 2.5mm² (stranded)
