Carrier 42S, 42C, 42V specifications Typical Drain Line Details 42D Unit Shown

42C,D,V DRAIN CONNECTIONS — Install drain line in accordance with all applicable codes. A continuous pitch of 1 in. per 10 ft of condensate drain line run is necessary for adequate condensate drainage. Insulate the drain line to prevent sweating. Extend the drain line straight from the drain pan before making any turns. The installer must provide proper support for the drain line to prevent undue stress on the auxiliary drain pan.

Install trapped drain line in accordance with all applicable codes (see Fig. 48). A drain trap may be required by local codes and is recommended for odor control. The differential height inlet to outlet must be at least 1-in. wg greater than the total static pressure of the unit. The differential height of the outlet to the bottom of the trap must not be less than the total static pressure of the unit.

Provide a trap of at least 2-in. near the end of the drain line to prevent odors from entering the rooms.

2 IN. MIN

CONDENSATE
PAN STUB-OUT	TRAP

7/8 IN. FIELD-SUPPLIED DRAIN EXTENSION

Fig. 48 — Typical Drain Line Details

(42D Unit Shown)

42C,D,V WATER SUPPLY/RETURN CONNECTIONS — Install piping in accordance with all applicable codes. Position valves over the drain pan. Be sure valves are in proper operat- ing position and are easily accessible for adjustment. See Fig. 44-47. Refer to Fig. 49 for copper water tube and joint material pressure ratings.

If coil and valve package connections will be made with a solder joint, care should be taken to ensure that the components in the valve package are not subjected to high temperatures, which may damage seals or other materials. Many 2-position electric control valves are provided with a manual operating lever. This lever should be in the OPEN position during all soldering operations.

If coil connection is made with a union, the coil side of the union must be prevented from turning (it must be backed up) during tightening. See Fig. 44-47 for common valve packages.

CAUTION

DO NOT OVERTIGHTEN! Overtightening will distort (egg shape) the union seal surface and destroy the union.

NOTE: The project specifications for system pressure, pres- sure drop limitations, and flow rate should be checked prior to selection of specific components or the valve package size.

42C,D,V STEAM CONNECTIONS — On units with steam heating coils, the maximum steam pressure applied to the unit should never exceed 10 psig. However, when steam is used on a 4-pipe application system with 1-row and 2-row coils the maximum steam pressure should never exceed 5 psig (suitable for only low pressure steam).

Do not drain the steam mains or take-off through the coils. Drain the mains ahead of the coils through a steam trap to the return line. Overhead returns require 1 psig of pressure at the steam trap discharge for each 2 ft elevation to ensure continu- ous condensate removal.

Proper steam trap selection and installation is necessary. As a guideline in creating a steam trap locate the steam trap dis- charge at least 12 in. below the condensate return connection. This provides sufficient hydrostatic head pressure to overcome trap losses and ensure complete condensate removal.

42C,D,V DIRECT EXPANSION (DX) REFRIGERANT PIPING — Use the condensing unit manufacturer's recom- mended line sizes and requirements. Suction line must be insulated for correct operation. Use refrigerant-grade copper lines only. The unit is not applied as a heat pump.

Thermostatic expansion valve (TXV) and sensing bulb are factory-installed on units when DX coil option is chosen with distributor and TXV.

NOTE: If a hot water coil is used in the reheat position, a field- supplied freezestat must be installed to protect the coil.

TEST AND INSULATE — When all joints are complete, perform hydrostatic test for leaks. Vent all coils at this time. Check interior unit piping for signs of leakage from shipping damage or mishandling. If leaks are found, notify a Carrier representative before initiating any repairs. Release trapped air from system (refer to Make Final Preparations section).

Never pressurize any equipment beyond specific test pres- sure. Always pressure test with an inert fluid or gas, such as clear water or dry nitrogen to avoid possible damage or injury in the event of a leak or component failure during testing.

CAUTION

All water coils must be protected from freezing after initial filling with water. Even if system is drained, unit coils may still have enough water to cause damage when exposed to temperatures below freezing.

Following the hydrostatic test, insulate all piping to prevent sweating.

To ensure compliance with building codes, restore the struc- ture's original fire resistance rating by sealing all holes with material carrying the same fire rating as the structure.

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