The type and specifications of Wuhan cable trays used in construction should be installed according to the design requirements specified in the design drawings. In engineering pre-settlement (such as preparing the bill of quantities, setting the engineering ceiling price, bidding quotations, or making engineering estimates), it must be strictly compiled based on the design drawings.

Special attention should be paid to the differences between the old and new quotas during implementation:

("The cable tray installation quota includes the installation of trays, covers, and grating plates. The old quota, except for certain parts, did not include the installation of covers. The old quota did not specify the installation of partitions, leading to some disputes in its application. The new quota clearly states that both partitions and covers are included.

Wuhan Cable Tray

Connecting bolts and fittings are purchased as part of the tray set. For calculation purposes in pre-settlement, they can be accounted for as 7% of the total weight or total cost of the tray. The old quota included connecting bolts within the quota. The interpretation also stipulates: whether hex bolts or T-bolts are used, the quota remains unchanged (the old quota was calculated based on hex bolts). The new quota for tray installation bolts

has comprehensively considered three fixation methods: bolts, welding, and expansion bolts. In actual construction, no adjustments are made regardless of the fixation method used.

The old quota divided tray installation into welding and bolt connection. During implementation, welding was often used, but in practice, bolt connection is more common. The new quota combines both welding and bolt connection.

Other points to note when implementing the quota:

The installation length of cable trays does not deduct the length occupied by tees, elbows, etc., but the cost of main materials should be calculated separately.

Cable supports, including uprights and brackets (including base weight), should be calculated according to design specifications. The installation quota for supports is based on finished products for main material costs. If fabricated on-site, the fabrication cost can be applied to the corresponding iron component fabrication quota, while the installation cost follows the support installation quota, with main material costs calculated based on the corresponding steel materials.

When the thickness of steel trays exceeds 3mm, the labor and machinery costs in the quota are multiplied by 1.2. Stainless steel trays follow the steel tray quota multiplied by a coefficient of 1.1.

The grounding connection between tray-type fiberglass cable troughs is already included in the quota and should not be calculated separately. If an additional grounding wire is laid inside the tray, the corresponding quota should be applied separately. (The grounding connection between cable trays is already included in the quota and should not be calculated separately. If an additional grounding wire is laid inside the tray, the corresponding quota should be applied separately.)