310.0 Condensate Wastes and Control
- A water level detecting device that will shut off the equipment or appliance in the event the primary drain is blocked.
- An additional watertight pan of corrosion-resistant material, with a separate drain line, installed beneath the cooling coil, unit, or the appliance to catch the overflow condensate due to a clogged primary condensate drain.
- An additional drain line at a level that is higher than the primary drain line connection of the drain pan.
- An additional watertight pan of corrosion-resistant material with a water level detection device installed beneath the cooling coil, unit, or the appliance to catch the overflow condensate due to a clogged primary condensate drain and to shut off the equipment.
The additional pan or the additional drain line connection shall be provided with a drain pipe of not less than 3/4 of an inch (20 mm) nominal pipe size, discharging at a point that is readily observed.
|EQUIPMENT CAPACITY IN TONS OF REFRIGERATION||MINIMUM CONDENSATE PIPE DIAMETER (inches)|
|Up to 20||3/4|
|21 — 40||1|
|41 — 90||11/4|
|91 — 125||11/2|
|126 — 250||2|
For SI units: 1 ton of refrigeration = 3.52 kW, 1 inch = 25 mm
The size of condensate waste pipes is for one unit or a combination of units, or as recommended by the manufacturer. The capacity of waste pipes assumes a 1/8 inch per foot (10.4 mm/m) or 1 percent slope, with the pipe running three-quarters full at the following pipe conditions:
|Outside Air — 20%||Room Air — 80%|
For SI units: °C = (°F—32)/1.8