C
OIL
O
PERATION
Maximum recommended steam pressure for
standard units is 15 psig at 275ºF. The
maximum recommended pressure for hot
water applications is 150 psig at 275ºF. For
higher operating temperatures and
pressures, special coils and ratings are
required.
U
NIT
O
PERATION
Most basic unit heater systems are
controlled by a room thermostat. Install
thermostat on an inner wall or column to
achieve optimum control of that area. Set
thermostat for desired temperature.
For steam systems, a low temperature set-
point limit could be used to prevent the fan
from blowing cold air when there is no steam
passing through the coil.
Small hot water systems could have the
circulating pump controlled directly by the
room thermostat. Large systems may use
zone valves to control individual unit heaters
where constant water circulation is used on
the pain system.
A louvered cone air diffuser is available as
an optional accessory for vertical unit
heaters.
M
AINTENTANCE
Motor Lubrication.
Standard motors are
pre-lubricated and normally are not
equipped with grease fittings. For motors
that are equipped with grease fittings,
contact the local motor manufacturer service
facility to obtain information on the grease or
oil type, and the method and frequency of
lubricating. The frequency of lubricating will
depend on operating conditions and length
of running time.
Unit Heaters
Installation & Operation Manual
3
www.sigmaproducts.com Tel: (905) 453-0446 Fax: (905) 453-0675
Warning:
Disconnect all power, steam or
water supplies before installing or
servicing the unit. Do not depend on a
thermostat or other switch as sole means
of disconnecting power. Always
disconnect power at the main breaker.
Caution:
Allow rotating fans to stop
before servicing to avoid serious injury to
fingers and hands.
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