Weather-Rite XT112 Installation, Operation & Service Manual - page 12
S
ERIES
XT I
NSTALLATION
, O
PERATION
AND
S
ERVICE
M
ANUAL
6
3.2 Purge of Supply Duct
If this heating unit is to be installed indoors, and its
outdoor air supply ducted from outdoors, ANSI
Standards Z83.4/CSA 3.7, Z83.18 and Z83.25/CSA
3.19 require that all supply duct shall be purged a
minimum of four times prior to any ignition attempt. If
the volume of the outdoor air supply duct exceeds
the heating unit’s ability to complete the required four
air changes prior to ignition, you must contact the
factory to purchase an extended purge card of the
appropriate duration to meet this requirement.
3.3 Hardware
Unless otherwise specified, all hardware must be
torqued to settings on
Note: Inlet hood opening shall not be installed with
inlet opening facing into the prevailing wind direction
in order to help prevent the possibility of moisture
entrainment.
Table 1: Recommended Torque Settings
Bolt Head
Grade Marking
Nut Grade
Marking
Bolt Size
Grade 2
Grade 5
10-24
27 in•lb
42 in•lb
1/4-20
65 in•lb
101 in•lb
5/16-18
11 ft•lb
17 ft•lb
3/8-16
19 ft•lb
30 ft•lb
Bolt Head
Grade Marking
Nut Grade
Marking
Bolt Size
Grade 8.8
Grade 10.9
M5
6Nm
9Nm
M6
10Nm
15Nm
M8
25Nm
35Nm
M10
50Nm
75Nm
M12
85Nm
130Nm
M16
215Nm
315Nm
8.8
10.9
8.8
10.9