Hi, We have an issue on site with an item of equipment. A safety Rep is declaring himslef unhappy with a practice that is being completed on a item of machinery in his area. We have risk assessed the task and feel confident the task is safe. Basically the equipment is fitted with interlocking connection switches over 3 separate guards which remove power to the machine and prevent re-energisation when removed. The task the operators are occasionally required to conduct is the removal of a jam with a section of the machine. In order to remove the jam the operator has to activite a light beam device, and physically remove 3 guards that are covered by interlocking devices (magnetic connections). The main panel on the machine identifies the 'safety device default' warning and the machine requires all guards to be returned and physically restarted on the control panel before any machinery will restart. The operators are told to remove the guards and vailidate the interlocks/safety features are functioning prior to starting the jam removal. The machine guards are also functionally tested and recorded at the start of every shift by operators on Pre-use Inspection form. The probabilty of all 3 safety switches failing together and the control panel malfunctioning while not being identified on a pre-use inspection would be like winning the lottery in my eyes! The jam removal involves removing the guards, cutting the vaccum package and removing the product from that section of the machine. Cutting away the plastic and resetting the web that feds the vacuum packaging. With the interlocking guards active the main residual risk that we have identified is residual heat within the sealing block that would take approx 30 mins to disapate according to the O&M Manual. We have since introduced requirement for Proban/heat resistant glove to worn if operating near to the heated block. The guards are protecting contacting with a clamping system that contents a heated element, conveyor mechanism and cutting blade that is contained with a metal enclosure and stays retracted within this enclosure when power is removed (guards removed). Because there is signage on the guards from the manufacturers stating power must be isolated before removing guards the HS Rep is adament we must Lock Out Tag Out for this operator task. This is based on the signage and the recent introduction of LOTO programme at our site for cleaning of machinery that happens on a daily basis. This however relates to machinery with no interlocking function and fixed guards that must be removed. I have explained this to him, reviewed the RA, tested the machine guards and devices with him but he is still not changing his mind. This machine is part of a fast moving production line and for this task of removing a jam would simply not be pratical to LOTO every time there is a jam. Production would be greatly effected and i believe the machine is designed by the manufacturer with these safety features for exactly these types of the tasks. All maintenance work is rightly completed under LOTO but not this. The signs on the machine are causing a real issue for us now. I would love any advice advice or feedback on this matter as it starting to get to the point where i'm questioning myself and the matter and have completely lost plot! (hence writing this at 4.00am when i should be sleeping instead!) Thanks,

I would have to disagree with you Pikeman. i used to work on thermoforming equipment and packaging lines. they regularly became jammed and the operator would simply open the guard once the machine had stopped clear the blockage and restart the equipment so long as all guards are interlocked and proved to be working then i don't see an issue. Fully LOTO the equipment would have meant 10-15 minutes before the machine could be restarted due to software loading and reaching back up to temperature. On a bad day you might get 100+ jams buy using the interlocks on the guards they can be cleared in seconds and the equipment re-started. the fact you insist that the operators check the machine has recognised the guards have been opened also is good idea maybe using a light system closer to where the guards are opened might help if the light is when the guards are open means that it is safe. Interlocks are very commonly used especially on large industrial presses for car body panels the press won't operate until the guard is closed then 50 tonnes come slamming down. So long as you can prove that the guard interlocks work (which you can as you do daily check) there is a procedure to ensure that when the guards open it puts the machine into a safety position (ie the machine won't start even if the green button is pressed. Then i believe you are doing everything correctly. Unfortunately some times safety reps have no understanding of H&S regulations etc and are there just as the voice of the employee they should be willing to accept the knowledge and experience of those with the qualifications who make the decisions. Also good to have the full story rather than two sentences we are then expected to comment on Phil

I agree with Phil that the principle of using interlocking for such access is acceptable. However this is slightly different from the need to access as part of the operation of the machine. i.e.placing material into the machine for work such as on a press so i would counsel some further checks. If as you say blockages are common place then that is a known factor for the machine design and must have been considered in the design and conformity assessment. My first stop would be the user manuals and manufacturer or suppliers to ask what the design says about removing blockages. If that is not possible the make sure you have another engineer confirm the arrangements as meeting the risk assessment. The confusion seems to centre on what "isolation" is required, total or just removal of power and prevention of reset until the operator is removed form danger. Feels like the latter is the most likely correct interpretation but it would be unwise for you to rely upon that opinion as I have not seen the detail, p48

I'm with Pikeman on this. I cannot get away from the fact that the manufacturer has placed this sign requireing power isolation. If that is ignored then you're stepping out on a limb. In the event of a worst case scenario youmight find it a lonely place. The interlocks can be checked but they are not a guarantee, only LOTO is. Check the following: 1. Does the sign re LOTO cover the entire thing or just one element? Sometimes your equipment might be made up of several individual units form different manufacturers. 2. Go through an exercise where you actually perform the LOTO so that you can be accurate wrt how long it will take. Make sure you check with mech & elec engineers with knowledge of the machine. Finally, check the facts of your situation and make up your own mind, don’t be bullied into something you later regret.

Well said Brent. The "We have risk assessed the task" part only works if the supplier of the equipment has followed the standards mentioned while designing the equipment. I also strongly agree that for the most part "machine manufacturers have no clue" but they "don't know they don't know" Cheers Tom Doyle Industrial Safety Integration.

I really can't see a big deal in locking-off the machine at the isolator. A few additional minutes at most, and a happy, secure workforce.

I'm with Phil on this one.

Brent made an implicit point in his technical response and once I had recovered from being told off I think it is important to highlight it once again. These things are, or should be, an inherent part of the design safety assessment of the machine and its safety control systems and is not something that a task based risk assessment would cover. It is either designed to be used in this way or it is not, we cannot tell from this distance. There are just too many variables that could impact on its design and safe use. What we can say is that the use of interlocking devices is one acceptable way of dealing with such "in use" matters but that they must be properly designed to meet the required standards and specific dangers. We can offer experience of other machines but that may or may not match the circumstance that the OP is facing. It is important to determine what that risk assessment says, if it cannot be found then it needs to be done. p48

Basically, you have to go right back to the begining....is the activity and the SSoW suitably described in the machine manufacturers instructions? If yes, contact them and confirm a suitable assessment has been undertaken as required by the specific standards and get their agreement that what you are proposing to do is what they have designed/assessed the machine for. If no, you will need to use isolation and lock out until you can devise and agree with the machine supplier a suitale SSoW.