DH Instruments VACUUM PUMP KIT FOR MOLBLOC-S Instruction Sheet

The use of a vacuum pump, connected downstream of
®
the molbloc-S , increases the usable flow range of
each element. The installation and operation of the
vacuum should be in accordance with all applicable
local electrical, plumbing, building, and safety codes.
This instruction sheet is a guide to the application of
the vacuum system and use with the molbloc-S and
molbox mass flow calibration system. Please follow
the recommendations and installation information
provided in the pump's operation manual published by
its manufacturer and provided with the pump.
Figure 1: Vacuum Pump
WIRING THE LEYBOLD SV25B
VACUUM PUMP
The power cord included in this kit, P/N 103486, is a
three-conductor plastic original equipment cord, rated
at 1875 Watts, 15A-125V. The conductor colors are
blue, brown, and green with yellow stripe.
1. Refer to Figure 1. Locate the terminal box on
the top of the pump, and remove the two
screws that hold the cover in place.
2. Remove the cover to expose the terminal
block.
3. Unscrew the safety collar and insert the cord
through the safety collar and into the terminal
box.
4. Refer to Figure 2. Locate terminal one and
attach the blue wire (neutral) to it.
terminal two and attach the brown wire (line)
to it. Locate the earth ground terminal off to
Installation and Use of Low-Flow
Vacuum Pump Kit for molbloc-S
the side in the terminal box and attach the green
with yellow stripe wire (earth ground) to it.
5. Tighten the safety collar until the power cord is
captured and cannot be pulled from the
terminal box.
6. Replace the cover and re-install the two
screws to secure it.
Figure 2: Wiring the Leybold SV25B Vacuum Pump
VACUUM PUMP INSTALLATION,
GENERAL CONSIDERATIONS
• The vacuum pump should be located in a place
where there is adequate ventilation for cooling.
Consideration of the noise and heat generated by
the pump should be made. It might be desirable
to install the pump in a location outside of the
laboratory in which the molbloc/molbox system
is operating.
• Caution should be exercised when calibrating in
gases other than air. Asphyxiation of personnel
within a confined space into which the pump
exhausts is a real threat when calibrating at high
flow rates.
Locate
outdoors or into a large ventilated space is
recommended.
P/N 401982
Instruction Sheet
Venting of the exhaust gas stream
®