Replacement of Chiller & Controls
|SERVICE(S):||Electrical, Mechanical, Building|
RME Services were contracted under JCT terms and conditions to replace the main chiller plant and fan coil unit controls throughout a three-storey building.
Works consisted of the following:
The decommissioning and removal of the existing basement R22 Carrier 30 HS chiller and associated air cooled condensers located on the ground floor and replacement with a new R407C Hitachi packaged chiller located on the ground floor. The existing chiller was decommissioned and removed from the basement plant room together with the air cooled condensers that were located to the rear of the building on the ground floor. Associated connecting pipework was also removed back to the plant room to facilitate the installation of replacement equipment. A new packaged Hitachi chiller was installed on the existing concrete base and new pipework was installed from the chiller to the plant room. New primary pumps were installed in association with the chiller and a new control panel MCC5 was installed to operate the chiller, pumps and associated controls. The controls were then incorporated into the buildings Building Management System to provide remote monitoring and set point control.
The replacement of the existing fan coil unit controls on each floor from those of the existing Johnson control manufacture to that of Trend. Each master fan coil unit has been equipped with a Trend IQL10 controller capable of operating the heating and cooling valves within the unit. This is carried out in conjunction with an air temperature sensor mounted within the unit. In instances where a further one or two units are located within the same space these are treated as slave units and controlled via the master unit controller. The wiring to each of these controllers has also been replaced in line with Trend specifications.
The replacement of faulty valves to a proportion of the fan coil units. During the initial survey a number of valves and actuators were identified as faulty. These were replaced with a new combined Honeywell valve and actuator.
The existing main electrical supply to the old chiller was removed from the basement plant room to the main electrical switch room. A new 240 mm 4 Core SWA supply was then installed to the new chiller location on the ground floor. In addition new power was installed to the new control panel from the adjacent sewage ejector plant room. New local supplies were also installed for the three network controllers located on each floor.