Teikoku USA | Chempump
Instruction Manual NC-Series 0220
9
2.3.2 Thermal Cutout
Unless otherwise specified, all Chempump pumps are fitted with
thermal cut-outs. The cut-out is a heat-sensitive bimetallic switch
mounted in intimate contact with the stator windings. It is to be
wired in series with the holding coil in the starter box by remov-
ing a jumper. Refer to
for TCO maximum holding coil
currents.
Thermal cut-outs in Class R insulated motors are set to open
at 415˚F. Depending on the application, specially set TCO's are
sometimes provided. The pump order data sheet indicates the
TCO setting. If the motor cuts out because of TCO action, there
will be a time delay before the motor can be restarted. The mo-
tor must be restarted manually.
DO NOT RESTART UNTIL YOU
DETERMINE THE SOURCE OF THE OVER-HEATING.
Table 2-2. TCO Maximum Coil Currents
115 Volt
3.1 Amps
230 Volt
1.6 Amps
460 Volt
0.8 Amps
Caution!
The thermal cutout switch does not provide protection
against fast heat buildup resulting from locked rotor con-
ditions, single phasing, or heavy overloads. This protection
must be provided for by the current overload relay heaters
in the magnetic starter. The rating of the heaters should
be high enough to avoid nuisance cut outs under running
loads, but must not be oversized. Refer to
for
starting and running electrical characteristics. It is recom-
mended that “quick trip”, class 10 or less, type heaters
be used.
2.3.3 Starting Equipment
Motor starters (normally not supplied with Chempump pumps)
should be sized to handle the load required per the National Elec-
trical Code (NEC). Start KVA, Full Load KW, Full Load amps and
Full Load KVA data are listed in
Thermal overload to protective devices in the starters should be
sized for the amperage shown on the Chempump nameplate.
DO NOT size heaters in excess of 10% of full load amp rating. In
order to provide complete protection for Chempump motors un-
der all conditions, it is recommended that “quick trip” (Class 10)
type Thermal overload to protective devices be used in the start-
ers where available. Standard type thermal overload to protective
devices can be used if these “quick trip” type thermal overload
to protective devices are not available. Standard thermal overload
to protective devices provide adequate protection for Chempump
motors under starting or normal running conditions, but require a
greater length of time than “quick trip” type thermal overload to
protective devices to cut out. This may not protect the meter if the
motor is subject to locked rotor or overload conditions. Also, see
,
,
,
for additional electrical wiring data for
the most common Chempump motor sizes to assist in the electri-
cal installation of the unit.
2.3.4 CASE I - 460 VOLT, 3-PHASE TEIKOKU. See
.
Typical 3-phase across-the-line magnetic starter with start-stop
push button station shown. Thermoswitch (thermal cut-out in-
side Teikoku motor) is wired in series with holding coil circuit by
removing jumper between over load cut-outs as shown.
Be sure to size heaters properly. Rating should be as close as pos-
sible to current draw noted on pump nameplate.
2.3.5 CASE II - All other voltages (not to exceed 600
volts), 3-PHASE TEIKOKU. See
.
Use transformer with primary and 115 volt secondary. Use prop-
erly rated holding coil (115 volt). Wire Thermoswitch as for 460
volt systems described in Case 1.
2.3.6 Variable Frequency Drive (VFD) Power Supply
NC-Series pumps can be operated with a VFD power supply. The
VFD should be a Pulse Width Modulated Drive selected for the
appropriate voltage class of the motor, i.e. 400V class for 460V
motors, and suitable to handle the full load current of the motor.
The VFD should always be sized based on full load nameplate
current and not the listed horse power (hp). Sizing based on hp
could lead to an undersized drive being selected. The drive should
be programmed to ensure a linear relationship between voltage
to frequency (V/F) and frequencies should be limited to the range
of 25-65 Hz. Operation at 65 Hz assumes the motor will not oper-
Table 2-1. Conditions Indicated on the TRG Meter
The TRG meter has a colored scale which is divided into three zones: Green (0 to 0.5), Yellow (0.5 to 0.75), Red (0.75 to 1)
AT TRIAL OPERATION
DURING OPERATION
Indication
Condition
Solution
Indication
Diagnosis
User Actions
Full scale
incorrect wiring
change power cable
connection
Green
Good
No action
Yellow to Red
phase failure
check connection of
cables
Yellow or scale increase of
> 0.3 from initial indication
Bearings worn to
caution level
Plan routine
maintenance
Green
normal
connection is correct
Red or scale increased of
> 0.5 from initial indication
Immediate
maintenance required
Shutdown immediately
and replace worn parts
Hazard!
Do not operate if TRG meter condition is RED.
