Chromalox PG405-5 specifications Wiring, Wrong, Right, Radiant, Heaters

WIRING

ELECTRIC SHOCK HAZARD. Disconnect all power before installing or servicing heater. Failure to do so could result in personal injury or property dam- age. Heater must be installed or serviced by a qualified person in accordance with the National Electrical Code, NFPA 70.

ELECTRIC SHOCK HAZARD. Any installation involving electric heaters must be performed by a qualified person and must be effectively grounded in accordance with the National Electrical Code to eliminate shock hazard.

1.Electrical connection to the type U-RAD Radiant Heater is made through the 7/8” dia. opening in the end of the terminal cover of the element assembly. A 1/2” flexible conduit connector is provided with each element assembly for this purpose.

2.Wiring should be run in flexible or rigid metal conduit and must be installed in accordance with the requirements of the National Electrical Code and such other local requirements by a qualified per- son as defined in the NEC.

3.Access to the element terminals is obtained by removing the mounting bolt and nut (see Figure 8, item 16 and 18 ) and slid- ing the terminal end of the element assembly out of the housing.

4.Wires supplying power to heating element terminals shall have insulation rated for 150°C minimum.

High temperatures will oxidize copper. Use only nickel-plated copper wire for supplying power to heater. Do not use aluminum conductors.

5.A sufficient length of this wire (not less than 12”) should be used to extend from each heater terminal into a connection box location where the temperature does not exceed 300˚F.

6.Assemble terminal, screw and wire as shown in Fig. 5.

7.Hold terminal with pliers and tighten the terminal screw securely with a screwdriver.

Note: Where circuit wiring is installed in locations of high ambient temperature, conductors should be insulated in accor- dance with requirements for temperature and voltage.

Wrong	Right
Radiant
Heaters
L1	L1
L2
	L2
Figure 6

8.SERIES CONNECTION of Radiant Heaters of equal volt and watt rating is permitted in all line voltages up to 600 volts. In making such series connections it is necessary to observe the “right” (series-parallel) connection rather than the “wrong” (parallel-series) connection both shown in Figure 6. If heaters are connected according to the “wrong” illustration, failure of any one heater will cause progressive failure of other heaters still operating.

3 Conductors

in 1 Conduit

A	B C	D E	F	Radiant
				Heaters

L1

L2

L3

3Conductors in 1 Conduit

Figure 7

9.DELTA CONNECTIONS — When heaters occur in multi- ples of three, they may be connected to, and balanced across, three-phase lines. The most commonly used connection is the delta connection illustrated in Figure 7.

Three phase Delta connections to minimize inductive effect in conduits are made per this diagram. The rule: run all 3 three- phase conductors in the same conduit as far as possible. For sin- gle-phase, run only two conductors and follow the same rule.

Figure 5