SIM100MOD datasheet(5/19 Pages) SENSATA

5 / 19 page

Preliminary

Rev 1.5

Sendyne SIM100MOD

This contact closes the circuit and current flows

through a person’s body. Note that although it is

shown that V

n < Vp in this example, an isolation fault

cannot be detected based solely on voltage readings.

The following illustrations show two examples where

an isolation fault may be present while V

n = Vp .

A “symmetrical” or “double” isolation fault may oc-

cur through insulation failures in power connectors

or other environmental and intrusion reasons and,

depending on the value of leakage currents, may cause

power loss, overheating and even fire. Detection of

these types of faults is an absolute requirement for the

safety of IT power systems.

Capacitive faults

Of equal importance to personal safety is another type

of hazard. While international standards do not yet

require it to be monitored, it is the hazard that can be

caused by excessive energy stored in the IT power sys-

tem capacitors. IT system designers ensure that design

values of Y-capacitors prevent energy storage beyond

the safety limit of 0.2 J. Sub-system failures, such as a

coolant leakage or personnel interventions, may alter

the originally designed capacitance values. In this case

energy discharged through a person’s body can create

a hazardous event as shown in Fig. 5.

Chassis

Figure 5: A capacitive fault will lead to excessive

energy stored

Note that the stored energy limits are set for the paral-

lel combination of all capacitances between the power

terminals and chassis.

Sendyne’s SIM100 is the only isolation monitor today

that dynamically tracks IT system’s capacitances and

reports the maximum energy that can be potentially

stored in them.

SIM100MOD Datasheet(PDF) 5 Page - Sensata Technologies, Inc.