McQuay IM 987 25
Mechanical Installation
Lifting Points
To determine the required lifting cable lengths and whether
four-point or six-point lifting is required, use Tables 4 and 5
and Figure 29.
Referring to Figure 29, note that dimension A is the distance
between the outer lifting points. The four outer rigging cables
must be equal to or longer than dimension A. Dimension B
shows the minimum distance between the outer and the inner
lifting points for six-point lifting. Use this to roughly
determine the required length of the middle cables for six-
point lifting. Determine dimension A by subtracting
dimensions X and Y from dimension Z (e.g., A = Z – X – Y).
• Where:
• Z = Total unit length in inches
(refer to certified drawings for this dimension).
• X = Outdoor/return air section length (refer to Figure 29 and
Table 5 for this dimension).
• If A 288" (7315 mm), 4-point lifting is sufficient.
• If A > 288" (7315 mm), 6-point lifting is required.
Figure 29: Unit Type RAH Lifting Points
Table 4: RAH X Dimension (See Figure 29) Economizer
Section
Type of economizer
section
047C 077C
100% OA 0 0
Plenum 48” (1219 mm) 72” (1829 mm)
0–30% OA 48” (1219 mm) 72” (1829 mm)
0–100% economizer 72” (1829 mm) 96” (2438 mm)
0–100% economizer with return fan 72” (1829 mm) 96” (2438 mm)
Table 5: RDS X Dimension (See Figure 29) Outdoor/return
Air Section
Outdoor/return air section 800C 802C
100% OA 0 0
Plenum 40” (1016 mm) 52" (1321 mm)
0–30% OA 40” (1016 mm) 52" (1321 mm)
0–100% economizer 40” (1016 mm) 52" (1321 mm)
0–100% economizer with 15" return fan 62" (1575 mm) —
0–100% economizer with 30" return fan 52" (1321 mm) 52" (1321 mm)
0–100% economizer with 40" return fan — 80" (2032 mm)
A
Z
X
4 Lifting Points
X
6 Lifting Points
B
A
Z
RDS 800: B Min. = 62" (1515 mm)
RDS 802: B Min. = 84" (2134 mm)
RAH 47: B Min. = 96" (2438 mm)
RAH 77: B Min. = 120" (3048 mm)
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