Bird Technologies 6730B Series - Manual (Page 26)

Diaphragm
and Coolant
Oil
Remove the diaphragm to replace or examine the coolant
oil. For replacement of the diaphragm and coolant oil fol-
low the steps below for the appropriate model.
CAUTION
Do not replace coolant with anything but the specified
fluid. The inner shell of the resistor housing is
contoured to the dielectric properties of this fluid. The
use of any other type of coolant will affect the electrical
performance of the load.
Models 6732B, 6734B, 6734B-030, 6737A and 6737-030A
1. Stand the load vertically, with the back end up.
2. Loosen the clamp screw until the clamp band is
released.
3. Remove the diaphragm cover and lift the dia-
phragm from the back end of the radiator tank.
Inspect the diaphragm. If it is no longer soft and
pliable or shows signs of surface cracks it should
be replaced.
4. The coolant oil level should be about one inch be-
low the top of the radiator cylinder. The coolant
should be clear to a light yellow color; if not, it
may be contaminated and should be replaced.
Model 6735-300A (No Diaphragm);
1. Place the unit on its back, connector up, by lift-
ing the radiator front. Do it carefully keeping the
topside always face up. The vent hole is so posi-
tioned on the topside that when the unit is up-
ended in this manner, the coolant level will
remain just below the vent hole and not spill out.
2. Loosen the 10-32 x 1-1/2 inch screw on the
clamping band.
3. Remove the clamping band and lift the load re-
sistor assembly out of the tank. Allow the excess
coolant to drip back into the tank before laying
the assembly aside.
4. At ambient room temperature, the coolant level
should be 4-3/4 inch (120 mm) below the top sur-
face of the load resistor assembly mounting ring.
The tank is factory filled to this level with 2.9
Bird Model 6730B Series Termaline Wattmeter
18