UK: An overnight ammonia leak at an ASDA distribution centre required safe and prompt attention from maintenance contractor Star Refrigeration.
Under a national contract, Star Refrigeration provides a preventative maintenance plan and ensures any faults are dealt with promptly and safely when these occur.
ASDA’s 500,000ft² food distribution centre in Rochdale handles up to three million cases of chilled and frozen food per week as well as other food products for the supermarket chain.
When Star’s monitoring hub in Glasgow registered that the plant had tripped out at 9pm one evening, standby engineers at the company’s Manchester branch were notified of a “low-stage drum high level” and attended site to address the situation.
The low-stage surge drum was full of refrigerant and had carried over to the compressors. One of the low temperature compressors had developed an ammonia leak, and the compressor had to be isolated from the ammonia system – however the concentration of ammonia in the plant room was too high to allow safe entry.
Star Refrigeration’s engineers followed the company’s specified action plan to drop the ammonia concentration in the plant room, including activation of local ventilation fans, and deployment of additional extract fans and ducting to ensure there were no ammonia levels above 25ppm.
Once the plant room was safe to enter, a plan was put in place to transfer liquid between the surge drums and fit a replacement valve. There were three Star Refrigeration engineers on site in addition to the customer’s engineers, working as a team to get the plant back up and running. The cold store plant was out of action for 11 hours in total which did not heavily interrupt business.
“What really impressed us about Star was the way our emergency was handled,” commented Colin Taylor, SHE Manager at the ASDA site. “The plant tripped out at 9pm, and with two senior engineers and a manager attending and working through the night, the cold store was working again by 8.30am the next day.”
ASDA requires 24/7 cover of its refrigeration plant including remote monitoring and planned preventative maintenance visits. Star is contracted to keep the plant safe and legal, with services including written schemes of examination, calibration of the ammonia detection system and other sub-contract works managed by Star Refrigeration. Working alongside Star the retailer has strict contingency planning procedures in place to ensure a rapid response in the event of a mechanical failure, supported by a qualified team of engineers from Star Refrigeration’s local branch.