Bird Technologies 8630B Series - Manual (Page 24)

Bird 8630B Series Moduload RF Load Resistor
8
pints (4.74 liter) of coolant. The coolant must be either; distilled water
or a mixture of distilled water and ethylene glycol.
Distilled water is the primary coolant for the Bird 8630 and 8630B.
Ethylene glycol should be added to prevent bacterial growth and
freezing; 10% – 35% ethylene glycol is recommended. Using at least
10% will prevent bacteria growth and 35% will protect against
freezing to –20°C.
Figures 3 and 4 shows the coolant’s freezing point for a given
percentage of ethylene glycol in the mix. The following example shows
the weights to make a 65% distilled water to 35% ethylene glycol
mixture in 1 and 5 gallon quantities.
The load’s electrical and thermal performance is impaired by
impurities or additives in the coolant. Impurities which accumulate
as scale on the resistor surface are especially damaging. Only use
distilled water or a mixture of distilled water and ethylene glycol as
coolant. To ensure proper mixing add the water first, then the
ethylene glycol.
Filling Coolant
Reservoir
The Bird 8630 and 8630B has a coolant capacity of about 10 pints
(4.74 liter). To fill the coolant, follow these steps:
1. Make sure the drain plug is in place. Check that the hose
connections are correct and properly tightened.
2. Remove the filler cap on top of the unit.
WARNING
Ethylene glycol is toxic. Do not take internally. Avoid contact with
eyes, skin, and clothing. Avoid breathing vapor. Wash thoroughly
after handling.
CAUTION
Use only distilled water or the supplied ethylene glycol as coolant.
Do not use tap water, automotive antifreeze, sealants, or leak
stopping material. Use of these materials will damage the
instrument and void all warranties.
Ingredient 1 Gal. (3.78 L) 5 Gal. (18.9 L)
Distilled Water 5.6 lb (2.54 kg) 28.0 lb (12.7 kg)
Ethylene Glycol 3.0 lb (1.39 kg) 15.2 lb (6.9 kg)
CAUTION
Operation without sufficient coolant can damage the unit.