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SECTION 6 – MAINTENANCE
6.0
Preface: The following is a description of the hard-
ware, diagnostics, and corrective action to maintain
a process being controlled by the Technologic
70E/70M.
NOTE: The following should not be interpreted as the
maximum configuration of this controller, rather this
describes its application as a technologic 70E/70M
only.
6.1
TECHNICAL OVERVIEW
The Technologic 70E/70M is a micro-processor
based dedicated pump controller unique to and
exclusively manufactured by ITT Bell & Gossett. All
aspects of this unit are strictly proprietary to ITT Bell
& Gossett.
It consists of 3 electronic assemblies. The first
assembly consists of 3 circuit boards, i.e., display,
keyboard, and central processor unit (CPU) and is
referred to as the operator interface panel (OIP).
This operator interface is connected (with ribbon
cable) to a large board assembly known as the input/
output (I/O) board. This board contains a 24 volt DC
power supply to power the unit, all I/O, and a limited
number of sensors. It also has the terminals to con-
nect to external devices. All hard wire interface to the
outside world resides on this board and is protected
from the external environment.
The third electronic assembly is the power board
which connects to the OIP with a special cable. This
board senses amps, voltage, and calculates the total
power for staging and display on the OIP.
6.2
DIGITAL INPUTS
The controller has provision for digital inputs with a
voltage operating range of 22 to 26.4 VDC. This sig-
nal voltage must be obtained from the on-board 24
VDC power supply. Eighteen terminals are provided
with 6 of these terminals used to connect to the 24
VDC power supply.
It is not recommended that other power sources
be used without factory approval.
The terminal will accommodate (2) No. 18 AWG wires.
6.3
DIGITAL OUTPUTS
The controller has provision for relay outputs to con-
trol 120V 50/60 HZ devices.
Sixteen terminals are provided. All terminals will
accept up to (2) No. 14 AWG wires.
The relays are not removable. If defective the I/O
board must be returned to the factory for repair.
All relays operate as single pole single throw. Com-
ponents are provided to reduce contact arc and ex-
tend electrical life.
6.4
ANALOG INPUTS
Analog inputs are provided on the I/O board for
process variables and for flow readout. All analog
inputs operate at 4-20mA. They may be powered
from 24 VDC on board or self powered, in any mix,
without isolators.
Each analog input has 4 terminals associated with it,
i.e., 2 for signal input, 1 for 24 VDC, and 1 for shield
chassis ground.
Each analog input terminal will accommodate (2) No.
18 AWG conductors.
6.5
MEMORY
6.5.1
The EPROM is the only removable chip. However, it
is not recommended that it be changed by other than
the factory.
The EPROM is programmed by ITT Bell & Gossett
and its code is copyrighted. On power up the soft-
ware version is displayed as FW RELEASE VX.XX on
the top line and unit assembly serial No. on the bot-
tom line.
6.5.2
The EEPROM holds all data entered by the operator.
It is not removable. Old data is erased with new. All
data may be erased by the factory at which time all
data reverts back to default values published else-
where in this manual.
6.5.3
The RAM chip is not replaceable and requires no
maintenance.
6.6
CPU
The CPU does not require any maintenance, and
cannot be replaced as a field repair.
6.7
POWER SUPPLY
The power supply provides 24 VDC for all digital and
analog signals. It is specifically rated only for the con-
troller and other loads should not be applied without
factory approval.
The power supply also supplies 5 VDC for all TTL
devices.
The power supply is protected with Fuse F1 located
near the 120 VAC line terminals.
6.8
DIAGNOSTICS (Service Test)
The Technologic 70E/70M has built in I/O diagnostic
capabilities activated with a SERVICE TEST key while
in normal message scroll. It consists of 2 menus, i.e.,
read only and read/write. Read/write overrides the
program and requires a security code.
NOTE: Service test cannot be used if any of the fol-
lowing occur:
1. Power is off.
2. Display and or the start/stop LED is off (red or
green).
3. Watch dog LED (CR6) on the I/O board on.
6.9
READ ONLY – Digital Inputs
6.9.1
To Enter – press CLEAR key twice and then press
SERVICE TEST key once while in normal scroll.
6.9.2
Display – numbers 1 through 12 (implied) on the top
line and status on the second line. Status is displayed
as a "1" for signal on and "0" for signal off.
17
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