b. Water Supply Connection. Attach a garden hose to the water
supply connection. Before turning on the water to supply the labora-
tory, make sure that the reservoir gate valve (15, fig. 2-3) is
c. Waste Drain Connections. Open the access door of the air
conditioner. Uncoil the plastic tubing and attach it to the drain.
Drop the tubing down outside the shelter to assure complete drainage
of all condensate away from the air conditioning unit and the labora-
Connect a length of garden hose to the sink drain and route it
to a drainage ditch or to a previously prepared sump.
Utility Equipment and Automatic Alarm System.
Utility Equipment and Electrical System.
The air in the laboratory must be purged of
combustion or toxic vapors before allowing
personnel to enter. The exhaust (air-purging)
system will operate for ten minutes. All other
electrical circuits in the lab are inoperative
during the purging cycle, but will activate
automatically at its completion.
(a) Description. The electrical system (fig. 1-7)
provides services to all laboratory electrical components, lights and
utility receptacles. The system is powered by a 15 kw, 60 Hz; 120-
208, vac generator through a four-conductor power cable. All of the
major circuits have either circuit breaker or fuse protection against
overcurrent. The electrical system includes an air-purging system
and a combustible gas alarm system to assure the safe operation of
1. Momentarily depressing the main power switch
S2 to ON causes relay K1 to be energized. Contacts KIA close,
sealing in K1. Contacts KIB close, starting the fan and timer.
2. After 10 minutes, timer contacts 7 and 8
close, energizing relay K2 and contactor K3. Contacts K3A, K3B and
K3C close, providing power to circuit breakers CB2 through CB6.
(These circuit breakers provide power to the laboratory internal
electrical components). Contacts K2A close, removing fan from KIB
If fan local control switch S3 is OFF, the fan will
be deenergized at this time. The electrical system
is now in the normal mode of operation.