Installation
15
4.4 Electrical Connections
DANGER
A qualified technician should make all electrical connections to ensure compliance
to all applicable electrical codes. If permanent connection (conduit) is required to
meet UL, CSA and other applicable instrument safety standards, an external power
disconnect switch must be installed. This power disconnect switch should be
located near the instrument.
4.4.1
Power Connections
The product enclosure is rated IP65; however, achieving this protection level
depends on the use of proper hardware in the installation of this product.
NEMA-approved conduit hardware is recommended. Select the style of conduit
hardware that will seal to the enclosure wall when using flexible or rigid conduit.
Remember to follow all local electrical codes for your area.
Note:
Power feeds (ac) to the
instrument which are not contained
in properly grounded metal conduit
can be a source of instrumentation
upset or failure if surge or transient
disturbance levels exceed those
levels specified for industrial type
products.
For process or industrial applications, the national electrical codes of most
countries require that ac service needs be hard-wired and contained in conduit
systems. This instrument has been designed to conform to this requirement. Hach
Company recommends conduit for two reasons:
1.
It is generally required by most local electrical codes.
2.
Use of metal conduit can improve immunity to lightning surges and ac power
transients.
Note:
If power cords are allowed by
local electrical code, a 125V
UL/CSA approved power cord with
an approved NEMA-style strain
relief and a standard 115V North
American-style plug
(Hach Cat. No. 46306-00) or a
230V VDE-approved power cord
with an approved NEMA-style strain
relief and a Continental European-
style plug (Hach Cat. No. 46308-00)
can be ordered.
Electrical and instrumentation standards require a local means of removing power
from the product. Since this instrument does not have an on/off switch, the
customer must provide one. This may be accomplished with a customer-supplied
power cord or switch box (see
). A power cord method is
only acceptable if local codes permit and the considerations outlined in this
section are addressed.
In hard-wired electrical applications the power and safety ground service drops
should be no longer than 6 meters (20 feet) unless metal conduit is used to shield
the ac power wiring. The wire should be no smaller than 14 gauge.
In applications where power cords are allowed and power surges and transients
are not a great concern, an 18 gauge, 3-conductor power cord (including a safety
ground wire) can be used, but its length must not exceed 3 meters (10 feet).
Power connections are made at the terminal strip that is accessible when the front
cover and internal shielding are removed. Use only provided cord connected
strain reliefs to ensure sealing and protection against dust and moisture. Use
NEMA sealing hardware as appropriate (see
).
A power source with 100–240 V ac ± 10% is acceptable for this instrument. The
power supply terminal strip can be removed from its housing for connections. For
best results, electrical connections must always remain dry and clean in order to
ensure reliable instrument operation. Ensure that the cables are positioned
correctly when opening the transmitter.
