Five Safety Rules; Permit To Work; Capacitors; Ct's - ABB MNS-Up Service Manual

S A F E T Y F I R S T
2.6

Five safety rules

The DEAD circuit condition must be established prior to commencement of work and must be ensured at the place of work
for the duration of work in compliance with the five safety rules (EN50110-1 2013 chapter 6.2):
1. Disconnect completely;
2. Ensure no re-connection is possible;
3. Verify that the installation is dead;
4. Carry out earthing and install any shorting links required
5. Ensure that any adjacent live parts are suitably shrouded and provide the required protection.
!
Any circuit that has not been proven dead is to be considered as LIVE.
2.7

Permit to work

Permission to start work shall be given by nominated person in control of electrical installation (plant-responsible person or
PrP) to the nominated person in control of any work activity (work-responsible-person or WrP). The permit to start working
must be recorded and signed by all parties in a Safety Permit to Work document.
2.8 Personal Protection Equipment (PPE)
Personal protection equipment refers to clothing and additional devices to enhance personal protection to a safe level while
working on electrical systems. Depending on the area of work certain level of PPE is required.
When working on or near live parts the minimum standard for clothing is that products shall be capable of withstanding
e.g. electrical arc with an incident energy of 8cal/cm
that the clothing provided must be manufactured and tested to the following standards:
• For IEC: Class 1 Garments to IEC 61482-1-2 (Formerly ENV 50354 and CLC/TS 50354).
Specific Risk Assesment and Arc Flash analysis shall be carried out and as per the task the minimum PPE should be decided.
2.9 Special considerations when working on electrical equipment
2.9.1

Capacitors

The power supply to a capacitor by a remote auxiliary power source, if any, shall also be isolated. When the system has
been isolated, allow the voltage stored in the capacitor to be discharged, the outgoing capacitor circuits must be tested for
discharged condition using voltage measurement device. The automatic capacitor must be installed in accordance with the
standards IEC 60831-1&2 and all national regulations.
2.9.2 CT´s
Ensure that the current transformer secondary circuits have been shorted when no load is connected.
2.9.3

Auxiliary or temporary supply

Ensure that any auxiliary supply that may be required to perform testing or commissioning tasks is securely switched off and
protected against operation while working on the electrical equipment.
—
1 Earthing and shorting is not mandatory as per EN 50110-1 2013 ch 6.2.5.2. However, earthing
becomes mandatory under the risks described therein and if also requested by local requirements or
customer guidelines and where provision is made for earthing or other proper means are available.
;
1
. For the majority of work on or near energised systems, this means
2
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