Machine 1 – Hydraulic Guillotine Shear
This case study is based upon a metal cutting guillotine available to purchase online from a
.au domain or ordered from a leading machinery supplier located in several capital cities
within Australia. From the surface it looks like a good deal for the price however, upon
reviewing the online brochure and manual, several machine and electrical safety concerns
can be found.
1. In breach of the Model Work Health and Safety Legislation 2011.
Regulation 191:
If the design of the plant includes an emergency stop control for the plant, the designer of the plant
must ensure that the design provides:
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(2)(c) that the stop control cannot be adversely affected by electrical or electronic circuit malfunction.
The emergency stop function of the machine could become adversely affected from:
• The emergency stop internal switch contact failing in a closed position.
• The emergency stop internal switch contact becoming detached from the push
button actuator.
• The hydraulic motor contactor welding in.
• A short circuit in the emergency stop wiring.
• A safety circuit relay welded in a closed position.
Each fault would result in the machine continuing to run even when the safety device is
pressed. These are commonly found electrical faults and the due to the design of the
system, can remain undetected which could be too late in some circumstances.
To prevent the emergency stop becoming adversely affected by a malfunction, the design of
the emergency stop circuit would need to include protective measures that provide
resistance against the safety function failing in a dangerous state. This is achieved by
applying the AS/NZS 4024.1 – Safety of machinery standard and using certified safety
components.
2. Non-compliant with Clause 3.3.2.6 of AS/NZS 3000:2018 Wiring Rules
The machine contains a mixture of 220VAC/110VAC control circuit voltages which pose an
electrical hazard due to the cables being unprotected from mechanical damage. The
location where installed contains a high likelihood of being damaged due to the ejection of
metal cuts from the guillotine. The cuts ejected from the rear of the machine are conductive
and normally sharp. The operator retrieves the cuts by hand within the area of unprotected
cabling and it is reasonably foreseeable that accidental contact could be made between the
cut piece of metal and cables.
3.3.2.6 Mechanical damage
Wiring systems shall be selected and installed so as to minimize the risk of
mechanical damage.
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(c) Provision of additional local or general mechanical protection.
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3. Potential for electrical hazards if no RCD protection installed
Under the new 2018 Wiring Rules new installations of final sub circuits would require RCD
protection, however there are several loop holes that exist which could lead to this
requirement being avoided.
a. The machine being directly wired into a new or existing 40A circuit – likely to
occur in an industrial workshop.
b. The machine being fitted with a 40A Plug and plugged into a new or existing 40A
outlet.
The above situations occur commonly within industry, generally to save costs or as
contractors seek to provide the most cost-effective solution in order to remain competitive
and obtain work. The same situation was applicable to the previous Wiring Rules (2007)
however the difference being RCD’s were required at 20A rather than 32A.
Adversely the cost saving comes at the expense of safety to the end user operating the
machine and several points exist where there is potential for an electrical hazard:
• The 220V Fluorescent Machine Lights (Figure 9 – ED1, ED2) which are normally
tucked under the front of the machine.
• The 220V Unprotected Cables supplying the Photo Electric Safety Sensors at the rear
of the machine (Figure 9 – A1-A3) where sharp conductive parts are retrieved.
• The 110V Emergency Stop Circuit (Figure 9 – SB1, SB2, SB6) including the foot pedal
with emergency stop pole which is subject to constant movement and often dragged
using the conduit.
• The 110V control circuit supplying standard control components.
Non-domestic and non-residential installations—Australia only
2.6.3.2.3.3 Requirements for additional protection
Additional protection by RCDs with a maximum rated residual current of 30 mA shall be provided for
final sub circuits with a rating not exceeding 32A supplying—
(a) socket-outlets;
(b) lighting;
(c) direct connected hand-held electrical equipment e.g. directly connected tools; and
(d) direct connected electrical equipment that represents an increased risk of electric shock. Factors
that may represent an increased risk of electric shock include but are not limited to— connected tools;
and direct connected electrical equipment that represents an increased risk of electric shock. Factors
that may represent an increased risk of electric shock include but are not limited to—
(i) external influences (refer Clause 1.5.14); and
(ii) type of electrical installation and processes being conducted type of electrical installation and
processes being conducted
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4. Suspected imitation electrical components.
a. The emergency stop function components listed in the manual are discontinued
according to the manufacturers website which gives reason to believe they are
counterfeit imitations which cannot be relied upon to perform any safety
function of a machine such as an emergency stop.
b. It’s difficult to tell from the picture of the electrical panel but the circuit breakers
appear to be a mix of Schneider Electric and Merlin Gerin (now discontinued and
sold as Schneider) This could be a generic picture as the circuit breakers listed in
the manual turn up as Chint circuit breakers. Either way, if item 4a appears to be
counterfeit, there is a good chance the rest of the components are too.
Unfortunately, it’s highly unlikely the purchaser will be taking this into
consideration as they normally seeking the best value for money and would
expect an Australian business to be providing a compliant machine.
c. It is also unclear if the electrical components used contain the Regulatory
Compliance Mark (RCM) as per Figure 8.
5. Integrity of the Photo Electric Safety Sensors at the rear of the machine
Under the Model Work Health and Safety Regulations 2011, the person in control of a
plant that contains a presence sensing safeguarding system at a workplace must keep a
record of safety integrity tests, inspections, maintenance, commissioning,
decommissioning, dismantling and alterations of the plant for 5 years or if the plant has
been altered for the life of the plant.
Now here is where it gets interesting, now unless the words have been coincidently
worded, safety integrity is known as Safety Integrity Level (SIL) in which case Australian
Standard AS 62061:2006 Safety of machinery—Functional safety of safety-related
electrical, electronic and programmable electronic control systems would need to be
applied to the machine in order to perform a test on the safety integrity which would be
through validation as per the standard.
It is almost certain this piece of machinery would not fulfil the requirements of the
above standard nor AS/NZS 4024.1 – Safety of machinery so how could a safety
integrity test be performed and validated at all?
The onus of the safety integrity of the machine and other requirements is transferred to
the owner of the machine, not the supplier.
226 Plant with presence-sensing safeguarding system—records
(1) The person with management or control of plant with a presence- sensing safeguarding
system at a workplace must keep a record of safety integrity tests, inspections,
maintenance, commissioning, decommissioning, dismantling and alterations of the plant
for the period set out in subregulation (2).
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Summary
Without reviewing the machine in full and based only off the information on the supplier’s
website and manual, multiples failures of safety can be found. This machine fails to comply
with the Model Work Health & Safety Regulations 2011 and AS/NZS 3000:2018 Wiring
Rules. If the machine was to be inspected in full, more safety issues are likely to be expected
as it is yet to be determined if the guarding is acceptable, if the locations of the PE safety
sensors are acceptable, and has the hydraulic system been design safely.
The majority of businesses purchasing this machine would be none the wiser believing it is
well priced and safe due to it featuring emergency stops and safety sensors, however, no
protective measures are in place to prevent or detect the safety functions failing in a
dangerous state. This exposes the business in control of the machine to some considerable
risk but, sadly, it’s the operators who expect to be provided with a safe workplace and
equipment that get the raw end of the deal. The above points tend to only be found after an
incident.
If the following voluntary Australian Standards were utilised the operator would have a
much safer machine that could be relied upon to shut the machine down in an emergency
situation.
AS/NZS 4024.1-2014 – Safety of machinery series
AS 62061:2006 Safety of machinery—Functional safety of safety-related electrical, electronic
and programmable electronic control systems
AS 60204.1 Safety of machinery—Electrical equipment of machines
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Case Study 1 – Machine 1 – Hydrauilic Guillotine
Figure 1 - Guillotine
Figure 2 – 110V AC cables supplying the PE safety sensors have no
mechanical protection which an electrical and machine safety
hazard as sharp pieces of metal are retrieved from this area.
Figure 3 - Electrical components appear to be counterfeit and
have no C-Tick Approval
Figure 4 - Emergency Stop discontinued and most likely
counterfeit resulting in compromised safety function
•
Figure 5 - Model WHS Regulations 2011 – Emergency Stop
Controls
Figure 6 - Model WHS Regulations 2011 - presence-sensing
safeguarding system - records
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•
•
•
Figure 7 - Foot Pedal containing 110VAC
Figure 8 - Regulatory Compliance Mark - RCM
Figure 9 - Electrical Schematic – 220VAC Lighting & PE Safety Sensors / 110VAC Emergency Stop & Control
*Machinery and suppliers name withheld for legal reasons.
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