Condensate Drain, Blow-Thru Units - Carrier 39T Installation, Start-Up And Service Instructions Manual

Condensate Drain —
line at the unit's drain connection; use 1
See Fig. 56 and 57 for correct drain layout.
To determine the trap dimensions for draw-thru units, cal-
culate the coil's maximum negative static pressure (P
Fig. 56). The maximum negative static pressure equals the
pressure drop for the mixing box damper, dirty filter, and
dirty coil, at the design flow. Add 1 in. to the pressure drop.
(P = negative static pressure + 1 inch.)
1
Traps on draw-thru units must store enough condensate to
prevent losing the drain seal at start-up. The ''Minimum
1 ⁄ P '' dimension ensures that enough condensate is stored.
2
1
Install a condensate-trapping drain
1 ⁄ -in. standard pipe.
4
Fig. 56 — Condensate Drain, Draw-Thru Units
Fig. 57 — Condensate Drain, Blow-Thru Units
To determine the trap dimensions for blow-thru units, find
the coil's maximum positive pressure (P
figure is normally the fan total static pressure (P
static pressure).
For all units, provide condensate freeze-up protection as
in
1
required. On units with internal spring isolators, be sure the
unit is mounted to allow sufficient clearance for the required
drain trap depth.
65
in Fig. 57). This
1
= fan total
1