
CHAPTER 3
–
INSTALLING THE MULTILOAD II/RCUII EXL
22
MultiLoad II/ RCU II Explosion Proof Lite (EXL) Installation Guide - Part # 6070
Recommended Wire Sizes and Torque for All Terminal Blocks
Three sizes of terminal blocks are used in the MultiLoad II/ RCU II products: 7.62 mm pitch (supply
power), 5.08 mm pitch (line voltage switching), and 3.81 mm pitch (serial communication, analog or dc
voltages). The 7.62 and 5.08 mm terminal blocks have an allowable wire size of 24 AWG
– 12 AWG
and should be tightened to 0.55 Nm +/-0.05 Nm (5 lb in +/- 0.4 lb in).
The 3.81 mm terminal blocks have an allowable wire size of 28 AWG
– 16 AWG and should be
tightened to 0.23 Nm +/-0.02 Nm (2 lb in +/- 0.2 lb in).
Electrical Supply Connections
The MultiLoad II/ RCU II may be equipped for either 85 -250Vac or 24Vdc operation. Verify the
power type before making any connections.
To reduce the risk of ignition in hazardous atmospheres, conduit runs must have seals Installed
within 18 inches (45 cm) of the enclosure.
Field wiring must have a temperature rating of 75°C or greater.
Cable Gland Entries
Five M20 x 1.5 mm apertures in the enclosure bottom are provided for the installation of cable glands.
A gland with the correct corresponding thread must be installed in the opening.
WARNING:
If there are unused holes, blanking elements satisfying the flameproof “d” method of
protection must be used. Blanking elements must be removable with the aid of a tool, ATEX
certified, suitable for Gas Group IIB and suitable for an ambient temperature range of -40 C to +60 C.
Do not route AC and DC wiring in the same conduit.
All wiring must enter the MultiLoad II/ RCU II enclosure through conduit fittings or cable glands in the
bottom of the enclosure. All conduit fittings or cable glands used must be appropriately-rated.
Wires must be stripped ¼” and fully inserted into terminal block with no bare conductor exposed.
Review section 3.5 for recommended wire size and torque values.
Both ac and dc input models require a safety ground connection as described in section 3.6.4 below.
A service loop is recommended for all wires and cables entering the enclosure.
Do not allow service loop cables to overlap the circuit boards. Coil any cable length in the
bottom of the enclosure. Keep AC wiring separated from all other wiring in the enclosure.
Wiring must comply with all local electrical codes.