Office Memorandum: RPC Tech Note 4
SLAC, Power Conversion Department
March 20, 2001
To: Steve St Lorant MS 20
From: Martin Berndt MS 49
Subject: Power for 70D43 Using Existing Supplies
The following is information relevant to the problem of providing power to the old LASS Dipole type 70D43 magnet that will be moved to ESA.
1.- Magnet data as culled from Slim Harris (RIP) handy little handbook:
Magnet width 70 inches
Magnet aperture 43 inches
Coil material Aluminum
Winding style Two sets of coils in parallel
Resistance of coil assembly 0.0813 Ohms, at 50^C outlet water temperature
Maximum current/voltage/power 6000 Amperes / 488 Volts / 2.93 MW
Water at maximum power 410 gpm
Temperature rise at max power 27^C
2.- Cable resistance from Building 108 to ESA. Using two existing water cooled cable runs, plus some short dry cable jumpers:
Cabling 1 to 2 milliohm.
This gives a total circuit resistance (magnet plus cable) of about 0.083 Ohms.
3.- Nominal capability of the PB202 and PB203 power supplies in Building 108 (generally called the 1.59MW supplies):
PB202 & PB202 supplies 3000 Amperes / 580 VDC / 1.75 MW each
Two supplies can be operated in parallel. Operation in series not recommended because of insulation voltage limits.
4.- Nominal power capability of the other 6 large supplies in Building 108 (generally called the 567KW supplies):
Six large supplies 2700 Amperes / 240 VDC / 650 KW each
Two of these supplies may be operated in series or in parallel.
1.- The 2 large supplies (PB202 and PB203) may be operated in parallel and should have no trouble delivering at least 5500Amperes total to the 70D43 magnet.
PB202 & PB203 in parallel into 70D43 5500 Amperes / 456 VDC / 2.50 MW
2.- Paralleling should be done at the magnet, using two existing water cooled cable runs between ESA and Building 108.
3.- If 410 gpm of LCW exceeds the water supply capabilities at ESA, a reduction in cooling water requirements could be allowed, if accompanied by proportionally reduced power
Current Magnet Power Cooling Water Requirement
6000 Amperes 2.93 MW 410 gpm
5000 Amperes 2.03 MW 285 gpm
4000 Amperes 1.30 MW 182 gpm
5.- There are some additional operational problems to look out for:
Distribution: Pete Segura MS 49
Tony Donaldson MS 49
John Beach MS 49
Dave Macnair MS 49
Steve Williams MS 75
Peter Bosted MS 44