Specifications

Facilities Requirements
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The Diamond G & K-series RF power supplies operate on 48 VDC.
Coherent offers DC power supplies (included in the K-series Perfor-
mance Package) that convert incoming AC power to the voltage
used by the laser. With the exception of an optional single phase
power supply for the G-series lasers, Coherent DC power supplies
operate on 3 phase current. These 3 phase power supplies may be
damaged by the loss of a phase in the supply current. A phase imbal-
ance detector should be installed to shut down input power upon loss
of a phase in locations where the electrical supply is subject to such
problems.
System Cooling
Diamond lasers are relatively insensitive to variations in cooling
water temperature. For most applications, any temperature in the
range of 10ºC (15ºC for GEM-series) to 35°C (30°C max for the
K-500) with regulation to ±4°C is adequate. Water lines should be
large enough for the flow to be maintained at or above the specifica-
tion requirement at all times. For runs under 50 feet (15 meters),
3/8 inch (9.5 mm) ID hose is satisfactory. If longer hoses than this
are needed, the diameter should be increased to 1/2 inch (13 mm).
Nylon reinforced PVC is a suitable material for flexible water hoses.
While the G & K-series laser will run quite satisfactorily on tap
water as long as its hardness is less than the equivalent of
250 mg/liter of CaCO3, most installations will use some form of
recirculating chiller to minimize water use. Recirculated water
should be filtered to remove particulate matter from the coolant, and
algaecide should be added to prevent biological fouling. For filtra-
tion, a Balston 53/18 filter with an LP-200-18-10 cartridge,
providing 75 micron filtration, is sufficient for any Diamond laser.
The GEM-series requires +25% Dow Frost coolant in order to avoid
damage to the aluminum cooling passages of the laser head.
Chloramine-T algaecide in the amount of 1 gram for every gallon of
chiller water volume will control algae growth. To eliminate prob-
lems from corrosion, the water loop should not contain aluminum or
carbon steel, and dissimilar metals should not be in contact with one
another. Stainless steel, copper alloys and plastic are the best mate-
rials for maintaining coolant quality.
Cooling water should be maintained above the dew point to avoid
condensation on laser optics and electronics. Damage from conden-
sation is not covered under the laser warranty. It is advisable, then,
in humid environments, to maintain the coolant temperature at or
above ambient and to circulate coolant at all times to avoid conden-
sation when the laser is not operating.