Posted: 25 February 2021
Based on the size, complexity and usage of the system, inspection visits at equal intervals can vary on a year-by-year basis as the conveyor system ages. The first visit would generally be within 3 months from acceptance of the agreement or a number of months from the last CSL inspection.
A conveyor system supplier normally bases their costs on full, unimpeded access to all the conveyors included in the maintenance service contract and could include additional costs due to access delays and wait times which are charged separately as per the pre-agreed T&M (Time and Materials) rate.
Any parts on the conveyor system which are found to require replacement there and then will be drawn from a stock of spares held by the customer according to the recommended spares lists which should be provided on completion of the installation and handover of the system. The customer will be responsible for ordering, storing and maintaining the quantities of spares on their site.
If replacement is practicable at the time of the visit (the conveyor system can be stopped for longer and the parts are available), this will normally be carried out at the time and the additional time for the repair and parts used will be noted and charged accordingly in addition to the cost of the inspection visit.
Should the conveyor system be required urgently, and further work is not practicable at the time of the visit (either through access not being possible or parts being unavailable), this would normally be carried out on a separate visit at an agreed time and the additional hours for the repair (plus any travelling time and costs) will be logged and charged accordingly in addition to the cost of the inspection visit.
The conveyor system supplier may require access equipment to reach high level conveyors which can be provided either by the customer or by the conveyor supplier at an additional cost.
Most conveyor system suppliers provide a report of their findings following each visit, highlighting to the customer any items which need repairs or needed a replacement (assuming they have not been attended to during the visit). All inspection/repair visits will normally have their times and durations logged on the conveyor system suppliers’ standard timesheets for the customers information.
Conveyor system “walk through” prior to carrying out the inspection.
Prior to stopping the ecommerce fulfilment, warehouse or factory conveyors and locking off the safety system, the visiting engineer will “walk” alongside the whole conveyor system to check for any obvious visual problems or excessive noise which may highlight issues which he needs to add to the report for checking once the conveyor system has been stopped.
Gravity, Powered Roller and Chain conveyors – package handling.
Depending upon the design of the conveyor system, different replaceable parts that are designed to wear, need to be checked such as the condition of roller drive belts, Lineshaft and its bearings plus the condition of the rollers and chains.
Any pneumatic devices on the conveyor system such as blade stop assemblies including pneumatic cylinders, transfers, sortation switches and line brakes are checked for wear and air leaks as are solenoid valves and piping.
Chain conveyors need different checks for possible wear/damage to chains, wear strips, sprockets and chain tensioners.
Drive motor/gearboxes, whether they are 3 phase or 24-volt motorised roller type, are checked to ensure they are secure in the conveyor frame with no loose cables, not overheating or any gearbox oil leaks.
Ancillary equipment such as gravity rollers, skate wheels, dead plates, guiderails, end stops, package positioning guides are also checked for issues.
Belt conveyors – package handling.
On any belt conveyor system, to gain access to the drive roller and belt tensioner, the safety guards are removed to check, and re-tension as required.
Depending upon the design and type of belt conveyor system, different moving parts need to be checked such as the condition of the belting itself, end terminal rollers and the slider/roller bed that the belt runs over.
On a belt conveyor system, the belting is visually and physically checked for the correct tension to avoid slippage which would cause excessive wear, for “out-of-track” to ensure they do not drift to one side which could damage the edge of the belting, and the belt joint is not coming apart.
Also checked on a belt conveyor system is the condition of roller bearings for drive/tension/tracking drums and the drive units for oil leaks and/or excessive noise.
Drive motor/gearboxes, whether they are 3 phase or 24-volt motorised roller type, are checked to ensure they are secure in the conveyor frame with no loose cables and not overheating.
On a belt conveyor, end terminal rollers on the drive end are normally lagged with a full width section of belting wrapped around their circumference for gripping the carrying belt and this is also checked that it is not coming loose and needs any attention.
Ancillary equipment such as belt support rollers, belt skid plates, guardrails, end stops, and package positioning guides are also checked for issues.
Roller and chain conveyors/90-degree transfers– pallets/bulk bins/IBC handling
On any powered roller or chain conveyor system, to gain access to the drive and chain/chain tensioner, the safety guards are removed to check/re-tension/lubricate as required.
Also, on a powered roller system, the covers that protect and cover the chains driving the sprocketted rollers are checked to ensure there are no safety issues to personnel.
Depending upon the design of the conveyor system, different replaceable parts that are designed to wear, need to be checked such as the condition of roller bearings, carrier chain guides/wear strips, chain tensioners, sprockets and their bearings, chain wear plus the general condition of the rollers and carrier chains checking for damaged rollers or slack chains.
Positioning stop/guide assemblies and direction change raise/lower transfers on both roller conveyors and chain conveyors are checked for wear and air leaks as are all pneumatic cylinders, solenoid valves and piping.
3 phase/415-volt motor/gearbox units are always utilised on heavy duty conveyors for handling large, bulky and heavy items up to and over one tonne such as pallets etc. These are inspected for oil leaks or excessive noise and checked to ensure they are secure in the conveyor frame with no loose cables and not overheating.
Ancillary equipment on a heavy-duty conveyor system such as fork truck barriers, personnel safety fences, guiderails, end stops, and positioning guides are also checked for issues.
Spirals Elevators and Vertical lifts.
Spiral elevators use a plastic slat chain as a conveying medium which has an integral steel chain running in a plastic guide underneath linking all the slats together and this needs lubricating and checking for the correct tension and adjusting if necessary.
Also, some spiral elevators have chain stretch sensors fitted as standard to synchronise two points on the chain with the sensors to prevent the spiral elevator from running if they are out of alignment so need checking to ensure any chain stretch is rectified before a stoppage occurs.
Spiral slats are inspected visually for damage/wear, as are the chain guidewheels, wear guides, transfer rollers and drive bands and replaced, as necessary.
On a vertical lift, the lift carriage assembly and integral belt or roller conveyor are checked for alignment and damage whilst the security and integrity of any personnel guarding, and safety interlocks are also inspected.
As Spiral and Vertical elevators are designed for lifting items up to several mezzanine floor levels or overhead across a factory floor, 3 phase/415-volt motor/gearbox units are always utilised due to the amount of power needed to overcome the friction.
This is due to handling large numbers of products continuously as on a spiral elevator or single heavier weights on a Vertical lift.
These motor/gearbox units on every elevator are inspected for oil leaks or excessive noise and checked to ensure they are secure on the elevator frame with no loose cables and not overheating.
Every conveyor system has electrical devices such as motors, photocell sensors, barcode scanners, solenoids, RFID readers, vision systems etc at strategic points along its length to control areas where decisions are made regarding the movement/sortation direction of products and therefore should be checked to ensure they are not damaged or misaligned.
Electrical items can be covered within an inspection and a suitably qualified engineer will undertake to replace or repair and will note down any obvious items within the report.
Cables wiring up all the electrical devices such as the motors, photocells, solenoids, roller sensors etc run around the whole conveyor system so should be inspected for damage and the cables are secured to the conveyor frame/cable trunking.
The main conveyor system electrical control panel (s) should be checked for damage and the touch-screen HMI (Human Machine Interface), whether mounted onto the panel door or on a remote pedestal, should be interrogated for information on reductions in operational/performance volumes and to check if there are any fault diagnostic issues.
It is rare for any software issues once the conveyor system is fully commissioned and operational but software interfaces with the likes of WMS/WCS/SCADA systems should be checked if any issues are reported or any operational philosophy changes are required.
Emergency callout for breakdowns.
Most conveyor system suppliers provide a service for emergency call-out, aiming to attend such a call-out as soon as possible subject to availability and location of an appropriate engineer who preferably knows the conveyor system on that site.
Emergency callout charges are normally based on time spent on site plus travelling time to/from the site together with the cost of replacement parts if required and would be subject to pre-agreed rates and conditions as agreed with the supplier.