Évaluations - 1, GPA: 5 ( )

Fabricant : Carrier Taille : 1.24 mb Nom Fichier : Langue d'enseignement:

8 — Typical Piping Connections for Face Split Coils 4 Fig. 9 — Recommended Filter-Drier(s) and Sight Glass Locations Table 5 — Filter-Drier Replacement Parts and Data FILTER-DRIER UNIT Part No. Qty Conn. Size Replacement Part No. Core Qty 38AD024 KH43LE123 1 5/s : Same 0 38AD028 KH43LE12) 2 5/s Same 0 38AD034 KH43LE 121 2 s/s Same 0 38AD044 KH49EA030 1 % KH29EZ050* 2 38AB054 KH49EA120 1 IVs KH29EZ050* 2 38AB064 KH49EA120 1 lVs KH29EZ050* 2 38AB084 KH49EA040 1 ll/8 KH29EZ050* 3 * Replaceable cores only Install field-supplied thermostatic expansion valve in liquid line ahead of each evaporator section. For two-step cooling, the solenoids used must be wired to be opened by control from a two-step thermostat For example: two solenoids may be used with three TXV’s — one of the solenoids serving a liquid line feeding two of the TXV’s. When three solenoids are used with three TXV’s, two of the solenoids must be tied in parallel with the thermostat to serve the one liquid line feeding the two TXV’s. The third solenoid operates independently for the other step of cooling. Suction Piping at Evaporator and TXV Bulb Location The purpose of these recommendations is to achieve good mixing of the refrigerant leaving the evaporator suction header for proper sensing by the TXV bulb. 1. A minimum of two 90° elbows must be installed upstream of the expansion valve bulb location. 2. The thermal bulb must be strapped to a vertical riser following the second elbow of item 1. This riser must be at least 15 pipe diameters high and the bulb should be fastened 10 pipe diameters above the preceding elbow. 3. Size the suction line from near evaporator thru the 15 diameter long riser for high velocity. Enter the suction pipe sizing charts in Carrier System Design Manual at corrected design tons (each evaporator split) and 80 feet equivalent length (for 2° loss). Choose the smaller size pipe, when reading falls between two sizes on chart. Since the selection of suction piping recommended for high velocity is approximately 20 ft equivalent length, this sizing method will result in about 0.5° friction loss for that section. If a 2° loss is allowed for the entire suction line, this leaves 1.5° for the balance of suction line and should be sized on that basis. This high-velocity sizing should be adequate for oil return up the 15 diameter long riser. It should be checked. If an oil return connection at the bottom of the suction header is supplied with an evaporator, this connection must be teed in ahead of first mixing elbow (Fig. 8). When the compressor is below the evaporator, the riser at the evaporator does not have to extend as high as the top level. After the 15 diameter riser has been provided, the suction may elbow down immediately. Safety Relief — A fusible plug is located on unit liquid line before liquid valve. WIRING AND ELECTRICAL DATA Power Supply — Electrical characteristics of available power supply must agree with unit nameplate rating. Supply voltage must be within tolerances shown in Table 6. Phase unbalance must not exceed 2%. Operation of unit on improper supply voltage or with excessive phase unbalance constitutes abuse and is not covered by Carrier Warranty. Power Wiring — All power wiring must comply with applicable local and national codes. Install a field-supplied branch circuit disconnect switch of a type that can be locked “Off’ or “Open.” Run power wires from the disconnect switch thru the power opening (H on Fig. 1) on unit and connect to terminal block just inside the opening. On 38AB084, there are two terminal blocks (on 208-volt and 230-volt units only). Each is limited to 350 MCM maximum wire size (see Table 7). These units are provided with two power openings to accommodate two conduit runs. For access to power opening and terminal blocks on 38AD044, unlatch the two latches on the outer hinged door and swing open outer door. Remove screws on barrier panel and remove barrier to expose wiring. 5 Table 6 — Electrical Data (3-Phase, 60-Hz) ^ !I| 387 420 350 210 «¡¡I 175 ¡68 , ,,140 , ~ÂmWÊÊÈT^ 420 lllll 420 ?10§Jiil 210 68 168 63^P^^y~636 590 Wmm 590 29S'WËÊm 295 236 ¡¡illil 236 WMÆS\ Shaded values are LRA drawn by first winding of -> part-winding start units (not standard on 38AB054.064, but may be field modified) See Note 1 Larger value is total LRA. FLA — Full Load Amps ICF — Maximum Instantaneous Current Flow (sum of LRA of last compressor to start and FLA of all other motors in unit, and control circuit current) LRA — Locked Rotor Amps -»• MWA — Minimum Wire Amps per NEC, Section 430-24 Values b...

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