Series Premier VS-VH
Page 37
LT135 Dec 2019
2. Vacuum Pump and Venting
Vacuum Pump
General Requirements
The Vacuum Pump (with permanently mounted motor affixed) is generally located at the height of the system,
bolted to a platform or support structure that is either suspended from the ceiling members or is bolted to a column
or building sidewall. The Vacuum Pump scroll is orientated for the preferred horizontal discharge, but can be
rotated 90 degrees in the field for vertical discharge.
(Refer to Figure 31, Figure 32 and Figure 33 for visuals of Vacuum Pump mounting options.)
*If a lengthy heater run has a 90 degree elbow with a short run to the Vacuum Pump, consider placing the Pump
somewhat off (past) the centerline of the connecting Tailpipe so that as the system grows the Flexible Boot
Connection in fact improves performance.
Safety Warnings
Confirm that the Vacuum Pump’s impeller rotates in the same direction indicated by the arrow on the pump scroll.
To reverse rotation, see instructions on the motor.
WARNING - DO NOT OPERATE THE VACUUM PUMP WHEN NOT INSTALLED
- Unguarded openings can entangle clothing and severe injury can result
- Unrestricted air flow into Vacuum Pump can cause the motor to overload
To ensure maximum safety, a vacuum proving switch is mounted near the inlet of the vacuum pump and electrically
interlocked to the burner power circuit. No fuel gas can flow, or ignition begin before the vacuum proving switch has
established the presence of a blower induced vacuum.
See the “Electrical Connections” section for details on wiring the switch.
Vacuum Pump Mounting
1.
Install Vacuum Pump as per designed system mounting location and position.
2.
Ensure that mounting supports are sufficient to withstand the weight and vibration of the Vacuum Pump
and Ventilation System. Welded link chain with a working load limit of at least 200 lbs. (91 kg) is
recommended for mounting vacuum pumps only.
3.
Install using the Vacuum Pump Mounting Kit if purchased. (Chain and threaded rods for ceiling mounting
are NOT included in package.)
4.
Ensure elevation of Inlet will allow for the alignment of the Tubing with a downward slope of ¼” per 10 ft. (7
mm per 3 m) towards the Vacuum Pump.
5.
Ensure that the isolators are placed between the Pump housing and the mounting supports to reduce
vibration transfer to the structure.
See Figure 31, Figure 32 or Figure 33 respectively for mounting type details.
