Specifications

Additional Info Required Before Quoting
On-Site Electrics
- 11 -
Air Compressors are available in a variety of electrical voltages, and in both single and three phase Units. Before
providing a quotation to your customer, ensure that you know the on-site electrics, and choose the correct
Compressor to suit.
Please find on 'Page 12’ electrical specifications pertinent to the standard Devair line of Compressor Units. It notes
information required to ensure that a customers site is capable of operating the Unit in a safe and correct manner.
1) Though single phase Units are available, use three phase Units when on-site electrics allow. Single phase
Units require much more power (and are therefore more costly) to both start and operate.
2) Single phase Units are available only in 5 HP and 7-1/2 HP configurations. Should your customer have
need of a larger Unit (but only has single phase power available), provide multiples of the 5 HP and 7-1/2 HP
Units.
3) Over the course of a day, on-site voltage may vary depending on demand. Motor manufacturers are aware of
this, and allow a variance of the nameplate Motor voltage +/- 10%.
Example: Nameplate voltage: 460 volt
Maximum allowable: 506 volt (460 + 10%)
Minimum allowable: 414 volt (460 - 10%)
When choosing a suitable Compressor Unit for certain on-site electrics, ensure that the building voltage (at
the Unit) is within the +/- 10% of the Motor voltage variance as noted above.
Example: On-site voltage: 208-60-3 (208 volt, 60 cycle, 3 phase)
Suitable Motor: 200 volt (200 + 10% = 220 max allowable)
Note: Though a 230 Volt Motor will handle the 208 on-site electrics, should the building voltage drop
below 207 volts (230 - 10%), premature Motor failure could occur. Use a 200 Volt Motor.
Premature Motor failure due to incorrect on-site voltage (in relation to Motor voltage) is not covered by the
manufacturers Warranty.
4) All electrical work should be carried out by a competent Electrician, and done in such a manner that it
meets all applicable Codes and Regulations.
Should you have any questions concerning electrical componentry required, local Codes or Regulations, etc.,
contact your Electrician, local governing authority, or the Compressor manufacturer.
5) All Devair Heavy Duty Cast Iron Compressor Units require a Magnet Starter to provide overload
protection to the Electric Motor. The Starter may be purchased with the Unit or separately.
6) Though every attempt is made to ensure that Compressor Units are manufactured to the governing
standards, any inspections required on site by a local authority are done at the customer's expense.
Helpful Tips to Remember Concerning Unit Electrics
On-Site Electrics
What other information do I need to know before quoting ?
Air Compressors
Information Bulletin IFB-01
March ‘07
For Sales & Service contact:
CENTRAIR Air Systems & Supplies 705-722-5747 [e-mail] www.centrair.ca