DH Instruments VACUUM PUMP KIT FOR MOLBLOC-S User manual

Installation and Use of Low-Flow
Vacuum Pump Kit for molbloc-S®
P/N 401982
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. Locate
terminal two and attach the brown wire (line)
to it. Locate the earth ground terminal off to
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. Venting of the exhaust gas stream
outdoors or into a large ventilated space is
recommended.

molbloc-S is a registered trademark of DH Instruments, Inc.
Document 560064B 040331
DH Instruments, Inc.
4765 East Beautiful Lane
Phoenix AZ 85044-5318
USA
Tel [phone]
Fax [phone]
[email protected]
www.dhinstruments.com
• In order to minimize the back-pressure applied to
the exhaust of the pump, plumbing should be as
short and as large in diameter as is practical, but
no smaller than the pump’s exhaust fitting size.
Inlet plumbing length and diameter should follow
the same guidelines in order to maximize the
efficiency of the vacuum pump. Restrictions in the
inlet plumbing will reduce the pumping speed of
the pump.
• In cyclic operations, such as flow meter calibrations
with molbloc-S, the pump should not be switched
off during cycles. Continue to run the pump with
the gas ballast valve open and the inlet port closed.
Power consumption is minimal when the pump is
operating at its ultimate pressure. Limit starting
the pump to no more than 5 or 6 times per hour.
DIMENSIONAL DATA, MM (IN)
Ø
INLET
NPT
Ø
EXHAUST
NPT
AMAX WMAX HMAX X Y
3/4 in. 3/4 in. 356
(14.0)
275
(10.8)
255
(10.0)
280
(11.0)
100
(3.9)
TECHNICAL DATA
Pumping Speed 25 cu m/hr, (14.7 cfm)
Average Noise Level 64 dB(A) (free field measurement at 1 m)
Main Voltage 110/115 (± 10 %) Volts AC (60 Hz),
1-Phase Supply
Motor Power 0.75 kW, (1.0 hp)
Nominal Speed 3 600 rpm
Weight w/Oil 27 kg, (59.6 lb)
Oil Capacity 0.5 l, (0.53 qt)
Inlet/Outlet Connection 3/4 in. female NPT
TOP VIEW SIDE VIEW
Please read and understand the enclosed installation and operation manual, material safety data sheet and all
other enclosed data. Personal injury and/or property damage could result if this equipment is not installed and
operated properly. This system should be assembled and operated only by personnel who have been instructed in proper
safety practices.