Vertiv Liebert Mini-Mate MT048 - Page 21

Do not install an external trap in the drain line. This line already has a factory-installed trap
inside the cabinet. Installation of a second trap will prevent drain-water flow and will cause the
water to overflow the drain pan.
This line may contain boiling water. Use copper or other material that is rated for handling
boiling water for the drain line. Sagging condensate drain lines may inadvertently create an
external trap.
A 3/4 in. (19.1mm) NPT-female connection is provided for the evaporator-unit condensate drain. The
evaporator drain pan includes a float switch to prevent operation if the drain line becomes blocked. This
line also drains the humidifier, if applicable.
Observe the following requirements and refer to Figure 4.1 below, when installing and routing the drain
line:
• The drain line must be sized for 2gpm (7.6 l/m) flow.
• The drain line must be located so it will not be exposed to freezing temperatures.
• The drain should be the full size of the drain connection.
• The drain line must slope continuously away from the unit.
• Do not externally-trap the drain line.
• The drain line must be rigid enough that it does not sag between supports, which
unintentionally creates traps.
• Use copper or other material suitable for draining water that can reach temperatures up to
212°F (100°C).
• When the evaporator is installed below the level of the gravity-fed drain line, the optional
condensate pump kit is required. See Condensate-drain Pump Kit on the next page.
NOTE: Remove the shipping band from the float switch in the evaporator pan before operating the
unit.
Figure 4.1 Correct and Incorrect gravity drains
Item Description
1 Correct drain installation.
2 Incorrect. Do not trap externally.
3 Incorrect. Sagging between supports and bowed line causes unintentional external traps.
4 Continuous downward slope away from the unit.
5 Unit
6 External trap
7 Unintentional traps from bowing of line. Lines must be rigid enough not to bow or sag between supports, creating a trap.
Table 4.9 Gravity-fed Drain Line Figure Descriptions
4 Piping and Refrigerant Requirements 21