How can we help you? Do you have questions about our products, spare parts or services? Send us your enquiry – our team will get back to you as soon as possible.
The Edwards EH250 is a Roots pump (Roots booster) with a pumping capacity of 310 m³/h at 50 Hz (375 m³/h at 60 Hz). The hydrokinetic drive allows operation from atmospheric pressure without a pressure switch or bypass. Ehrler & Beck advises on selection, backing pump and service.
Edwards EH250 – Roots pump with hydrokinetic drive
The EH250 belongs to Edwards' EH series of mechanical boosters (250 to 4200 m³/h). It has a pumping capacity of 310 m³/h at 50 Hz and 375 m³/h at 60 Hz and is combined with a suitable backing pump to improve the pumping speed and ultimate pressure of a system. The motor delivers 2.2 kW; the pump weighs 75 kg and is air-cooled.
Hydrokinetic drive
The motor drives one of the rotors via a fluid coupling. At a high gas load the speed of the rotors drops; as the gas load decreases they accelerate to full speed. The pump can thus be operated from atmospheric pressure over the whole vacuum range without overloading the motor – pressure switches, bypass lines or frequency converters are not needed. This limits the differential pressure across the pump, on the EH250 to 0–180 mbar at 50 Hz and 0–150 mbar at 60 Hz.
Typical applications
Edwards names, among others, semiconductor manufacturing, thin-film coating, vacuum impregnation, vacuum distillation, vacuum metallurgy, oil drying and degassing, vacuum packaging, low-density wind tunnels, pharmaceutical freeze drying, steel degassing, space simulation and CO₂ lasers.
Versions of the Edwards EH250
The EH250 is available as an HC version for hydrocarbon oil (oil included) and as a PFPE-prepared FX version (oil separate), each with IE3 motor for 380/400 V 50 Hz (Europe/China), 230/460 V 60 Hz (USA), 200 V 50 Hz and 200/380 V 60 Hz (Asia). The market details come from the Edwards webshop. The standard pumps are not azide-compatible, because cooling coils made of copper that come into contact with the process are fitted.
Advice and service
Ehrler & Beck supports you in selecting the right combination of backing pump and booster, supplies oil and spare parts and carries out maintenance and repair.
Pumping speed 50Hz
310
Pumping speed 60Hz
375
Rated motor power 50Hz
2.2
Rated motor power 60Hz
2.2
Motor efficiency class
IE3
Weight
75
Length
70.5
Width
30.5
Height
27.2
Inlet connection flange
ISO63
Outlet connection flange
ISO40
Noise level
70 dB(A)
Cooling method
Air cooling
Oil type
Ultragrade 20, XTRAGRADE ADVANCED 168
Additional technical data
Technical data
Value
Design
Roots vacuum pump with hydrokinetic drive, air-cooled
Version
HC (hydrocarbon oil): 3Ph 380/400 V 50 Hz, IE3 (Europe/China)
Pumping capacity (displacement) 50 Hz / 60 Hz
310 / 375 m³/h
Max. differential pressure (limited by the hydrokinetic drive) 50 Hz / 60 Hz
0–180 / 0–150 mbar
Max. outlet pressure
1000 mbar absolute
Speed 50 Hz / 60 Hz
0–2900 / 0–3500 min⁻¹
Motor power
2.2 kW (50 and 60 Hz)
Motor efficiency class
IE3
Sound pressure level (1 m, < 0.1 mbar, 50 Hz)
70 dB(A); at 60 Hz or a higher inlet pressure approx. 5 dB(A) more
Mass
75 kg
Dimensions L × W × H
705 × 305 × 272 mm
Connections, inlet/outlet side
ISO63 / ISO40
Oil
Ultragrade 20
Oil fillings
hydrokinetic drive/gearbox 1.5 l, shaft seal reservoir 0.125 l
Ambient temperature (operation)
−8 to 40 °C
Type of protection
IP55
Product name
Part number
Ultragrade 20, 1 litres (HC versions)
H11024015
Ultragrade 20, 4 litres (HC versions)
H11024013
Fomblin grease AR555, tube 100 g (EH250FX/EH500FX)
Edwards EH500Pumping speed 505 m³/h
Edwards EH1200Pumping speed 1,195 m³/h
Edwards EH2600Pumping speed 2,590 m³/h
Edwards EH4200Pumping speed 4,140 m³/h
